FUE-T07: use meter label directly as energy-cost HA device name (drop 'Energy Cost' prefix)

FUE-T06: trigger HA discovery republish after meter declare/update
FUE-T05: anchor energy-cost HA device identity to active meter (uuid id, label name, empty when none)
2026-06-25 21:28:13 +02:00 · 2026-06-25 20:54:42 +02:00 · 2026-06-25 20:43:07 +02:00 · 2026-06-25 20:20:01 +02:00 · 2026-06-25 18:36:46 +02:00 · 2026-06-25 18:33:42 +02:00
158 changed files with 55899 additions and 341 deletions
@@ -28,3 +28,38 @@ TICKTICK_CLIENT_ID=
 TICKTICK_CLIENT_SECRET=
 TICKTICK_TOKEN=
 HOME_ASSISTANT_ACTION_TASK_PROJECT_ID=
+
+# Optional: Modbus polling (global kill-switch; default false — opt-in).
+# MODBUS_POLLING_ENABLED=false
+
+# Optional: MQTT broker connection.
+# Leave MQTT_ENABLED=false (or unset) when MQTT is not needed.
+MQTT_ENABLED=false
+MQTT_BROKER_HOST=
+MQTT_BROKER_PORT=1883
+MQTT_USERNAME=
+MQTT_PASSWORD=
+MQTT_TLS_ENABLED=false
+
+# Optional: Home Assistant MQTT Discovery.
+# Requires MQTT_ENABLED=true and a running MQTT broker.
+# HA_DISCOVERY_PREFIX is the config topic prefix (must be "homeassistant" for HA auto-discovery).
+# HA_STATE_TOPIC_PREFIX is the prefix for state/availability topics (separate from discovery).
+HA_DISCOVERY_ENABLED=false
+HA_DISCOVERY_PREFIX=homeassistant
+HA_STATE_TOPIC_PREFIX=home_automation
+
+# Optional: DSMR smart-meter ingest via MQTT (M6; default off — opt-in).
+# Set DSMR_INGEST_ENABLED=true to subscribe to the DSMR MQTT topic and
+# store 10-second downsampled telegram frames in dsmr_reading.
+# DSMR_INGEST_ENABLED=false
+# DSMR_MQTT_TOPIC=dsmr/json
+# DSMR_SAMPLE_INTERVAL_S=10
+# DSMR tariff topic: publishes "1" (dal/off-peak) or "2" (normal/peak).
+# Empty string disables tariff-aware pricing (buy/sell_price_now always show normal rate).
+# DSMR_TARIFF_TOPIC=dsmr/meter-stats/electricity_tariff
+
+# Optional: Tibber dynamic pricing credentials (M6).
+# Only used when an active energy contract with kind=tibber is configured.
+# TIBBER_API_TOKEN=
+# TIBBER_HOME_ID=
@@ -36,14 +36,29 @@

 - **默认逐步**：给一个 milestone 文档，按其中原子任务**一步一步**实现。
 - **(a) 只实现一步**：用户说"只实现一步 / 这一个任务"时，**只做那一个任务卡**，跑完校验闸门后停下，等用户确认，不要顺手往下做。
- **(b) 完成整个 milestone**：仅当用户在提示词里**显式要求启用 sub-agent 并指定模型**时，才用指定模型起 implementer sub-agent，按任务依赖顺序跑完整条链。
- **Sub-agent 纪律**：只在用户显式要求时才 spawn sub-agent；单步/小改动在主线内联完成。起 sub-agent 时用用户**指定的模型**（Agent 工具的 `model` 覆盖）。
+- **(b) 完成整个 milestone**：仅当用户在提示词里**显式要求启用 sub-agent**时，才起 implementer / reviewer / fixer sub-agent（模型用下方**『默认模型档位』**，用户人工指定则覆盖），按任务依赖顺序跑完整条链。
+- **Sub-agent 纪律**：只在用户显式要求时才 spawn sub-agent；单步/小改动在主线内联完成。起 sub-agent 时按下方**『默认模型档位』**选择模型（用户人工指定则以人工指定为准），用 Agent 工具的 `model` 字段落实。

-### 角色（Orchestrator → Implementer → Reviewer）
+### 默认模型档位（实现模式 sub-agent；可被人工指定覆盖）
+
+起 implementer / reviewer / fixer sub-agent 时，**默认**用下列模型档位，无需用户每次人工指定：
+
+| 角色 | 默认模型 | 推理档位 |
+| --- | --- | --- |
+| **Implementer** | **Sonnet** | high reasoning effort |
+| **Fixer**（返工） | **Sonnet** | high reasoning effort |
+| **Reviewer** | **Opus** | extra-high reasoning effort |
+
+- **人工指定覆盖**：若用户在提示词里**显式指定了其他模型**（针对任一角色），则**以用户人工指定为准**，覆盖上述默认。
+- 用 Agent 工具的 `model` 字段落实模型选择；该字段当前仅支持 `sonnet` / `opus` / `haiku` / `fable`。
+- **推理档位说明**：Agent 工具未暴露独立的 reasoning-effort 旋钮，"high / extra-high reasoning" 通过 spawn prompt 里的显式指令传达（要求 implementer/fixer 动手前充分推理边界条件；要求 reviewer 以对抗性外部审计心态最高强度复核）。若所在 harness 提供真正的 effort 设置，则一并按此档位设置。
+
+### 角色（Orchestrator → Implementer → Reviewer → Fixer）

 - 我（主线）= **Orchestrator**：挑依赖已满足的下一个任务、派发、转述结果、维护任务 `Status`。
- **Implementer**（便宜模型，用户指定）：一次一个任务，严格按任务卡，不扩范围。
- **Reviewer**（强模型，用户指定）：实现完成后起 Reviewer sub-agent，按任务卡 `Acceptance criteria` + `Reviewer checklist` 复核、**独立重跑校验闸门**，驱动 implementer 返工直到本轮 PASS。
+- **Implementer**（默认 **Sonnet**，high reasoning；见上方『默认模型档位』）：一次一个任务，严格按任务卡，不扩范围。
+- **Reviewer**（默认 **Opus**，extra-high reasoning）：实现完成后起 Reviewer sub-agent，按任务卡 `Acceptance criteria` + `Reviewer checklist` 复核、**独立重跑校验闸门**，驱动返工直到本轮 PASS。
+- **Fixer**（默认 **Sonnet**，high reasoning）：按 reviewer 的编号返工清单返工；**每轮返工起一个干净的 Fixer**（与首次实现的 Implementer 分开冷启动），先读对应 `review-notes/<task>-review-<n>.md` 再改。

 #### Reviewer 盲审纪律（M1 教训）

@@ -101,7 +116,9 @@ python scripts/export_openapi.py && git diff --exit-code openapi/   # 改了路
 ## Commit 规范（重点）

 ### 分支
- 每个 milestone/feature 一个分支（如 `feature/m1-db-consolidation`），**不在 `main` 上直接提交**。
+- **本仓库是个人单用户项目：默认直接在 `main` 上开发**，不强制 feature 分支，**直接提交并 push 到 `main` 是允许的（无需开 PR）**。
+- 仍保持**每个任务一个干净 commit**（message 前缀任务/里程碑 ID）。改动较大想隔离时可临时开分支，用完**快进合并**回 `main`（保持线性历史），非必需。
+- 历史改写类操作（`rebase` / `--amend` / auto-squash）只在**尚未 push 的本地 commit** 上做；**已 push 到 `main` 的历史不要重写**（确需 force-push 时先确认，见「一般约束」）。

 ### 一轮实现完成（用户确认「实现完成」后）
 - 准备好**这一轮的 commit message** 并提交，作为本轮的 **base commit**。
@@ -130,7 +147,8 @@ python scripts/export_openapi.py && git diff --exit-code openapi/   # 改了路
  - autosquash **改写历史**：仅在 push / 开 PR **之前**做。若该分支已 push，需要 force-push——属对外操作，**先取得用户确认再做**。

 ### 一般约束
- commit / push 只在用户要求时进行；push、force-push、开/改 PR 等对外操作先确认。
+- **个人单用户仓库：直接 commit 并 push 到 `main` 已获授权**——在校验闸门全绿、一轮工作完成时即可提交 / 推送，无需逐次征求同意。
+- 仍需**先取得用户确认**的操作：**force-push / 改写已推送历史**，以及**打 tag**（会触发镜像 CI / 对外发布；且打 tag 前须按下方「发版前置走查」真跑一次 `docker build`）。

 ## 发版前置走查（打 tag 前必做）

@@ -6,14 +6,21 @@

 - FastAPI Web 应用（React SPA 前端 + JSON API）
 - SQLite + SQLAlchemy + Alembic 的单库结构
- username/password + server-side session 鉴权
+- username/password + server-side session 鉴权（含登录加固，见下文）
 - runtime config 页面与 app DB 持久化
 - public IPv4 monitor、历史持久化与定时检查
 - SMTP 配置、测试发信与 public IPv4 changed 邮件通知
 - location recorder
 - poo recorder
- Home Assistant inbound / outbound integration
+- Home Assistant inbound / outbound integration（REST 通道）
 - TickTick OAuth 与 action task 集成
+- **Modbus 设备采集**：通过 YAML profile（首个：SDM120 电表）按设备周期轮询 Modbus-TCP 网关，解码工程量并落通用读数表（`modbus_device` + `modbus_reading`）
+- **MQTT + Home Assistant Discovery**：以可勾选方式把 Modbus 设备/工程量注册为 HA device/entity（含 binary_sensor online），state 周期发布；配置变更可重连重发
+- **前端侧边栏 + Energy 视图**：侧边导航替换顶栏；Energy 页管理 Modbus 设备、展示最新读数与 Recharts 走势图；Config 页 Accordion 分区展开；Expose 设置勾选 HA 可暴露实体
+- **DSMR 实时电表接入**：订阅 DSMR Reader 的 `dsmr/json`（每秒一帧）、整帧 JSON blob 按 10 秒降采样落库（`dsmr_reading`）
+- **通用电价合同层**：YAML profile 定合同结构（manual 固定/双费率 / tibber 动态电价）；`EnergyContract`+`EnergyContractVersion` 存 UI 可填的数值，改价加新版本旧版本保留；price strategy 按 kind 出价
+- **实时买卖电费计算**：每 15 分钟按寄存器差值（`_1`=dal/低、`_2`=normal/高）× 买/卖价算计量电费，快照不可变；日/月/年汇总加固定费减 heffingskorting
+- **反哺 Home Assistant Energy**：当前买/卖价 + 累计买电支出/卖电收入（`total_increasing`）发成 HA 实体，可直接挂 HA Energy 仪表盘
 - pytest 测试与 OpenAPI 导出脚本
 - Docker / Compose 部署入口

@@ -30,6 +37,13 @@
 - public IPv4 当前状态与变化历史
 - location 记录（`location` 表）
 - poo 记录（`poo_records` 表）
+- Modbus 设备定义（`modbus_device` 表）
+- Modbus 通用读数（`modbus_reading` 表，JSON payload）
+- HA 实体暴露开关（`exposed_entity_toggle` 表）
+- DSMR 电表实时读数（`dsmr_reading` 表，整帧 JSON blob，10s 降采样）
+- 电价合同（`energy_contract` 表）与版本（`energy_contract_version` 表，values JSON）
+- Tibber 15 分钟电价缓存（`tibber_price` 表，不可变）
+- 每 15 分钟计量电费（`energy_cost_period` 表，快照价，不可变）

 配置层只保留一个数据库环境变量：

@@ -41,7 +55,7 @@
 python -m scripts.run_migrations
 ```

-该命令会通过 Alembic 将 `app.db` 初始化或升级到最新 head（含 `location` / `poo_records` 表）。
+该命令会通过 Alembic 将 `app.db` 初始化或升级到最新 head（含全部表，包括 M5 新增的 `modbus_device`、`modbus_reading`、`exposed_entity_toggle`，以及 M6 新增的 `dsmr_reading`、`energy_contract`、`energy_contract_version`、`tibber_price`、`energy_cost_period`）。

 ## 当前目录

@@ -49,7 +63,7 @@ python -m scripts.run_migrations

 - `app/`: FastAPI 应用代码（包含 JSON API、业务服务、数据模型）
 - `frontend/`: React SPA 前端（Vite + React + TypeScript + Mantine）
- `alembic_app/`: App DB 的 Alembic migration 环境（同时管理 `location` / `poo_records` 表）
+- `alembic_app/`: App DB 的 Alembic migration 环境（管理所有表，含 M5 新增的 `modbus_device`、`modbus_reading`、`exposed_entity_toggle`，以及 M6 新增的 `dsmr_reading`、`energy_contract`、`energy_contract_version`、`tibber_price`、`energy_cost_period`）
 - `tests/`: pytest 测试
 - `docs/`: 当前系统说明文档
 - `scripts/`: 辅助脚本，例如 OpenAPI 导出
@@ -128,6 +142,7 @@ M2 用 React SPA 取代了原有 Jinja 服务端模板，由 FastAPI 同源托
 - **Vite + React + TypeScript + Mantine**（组件库）
 - **TanStack Query**（数据请求/缓存）
 - **Leaflet / react-leaflet**（地图与热力图）
+- **Recharts**（Energy 视图走势图，M5 引入）
 - **openapi-typescript + openapi-fetch**（类型化 API client，由 `openapi/openapi.json` 生成）

 ### 本地开发（前端）
@@ -177,7 +192,7 @@ npm run build        # 构建，确认产出 dist
 - App DB：`sqlite:///./data/app.db`
 - 数据目录：`./data/`

-所有模型（auth / config / public_ip / location / poo）共用同一个 `Base`，均通过单一 Alembic 链管理：
+所有模型（auth / config / public_ip / location / poo / modbus / expose）共用同一个 `Base`，均通过单一 Alembic 链管理：

 - Alembic 环境：`alembic_app.ini` + `alembic_app/`
 - 统一 migration job：`python -m scripts.run_migrations`
@@ -228,6 +243,195 @@ React SPA 主要页面路由（客户端路由，均由 FastAPI fallback 到 `in

 无论是本地 `host:port` 还是反向代理后的域名访问，登录成功后进入 SPA 首页（`/`）。

+## M4 登录加固
+
+M4 在基础鉴权之上叠加了三层防御，详细说明见 [`docs/auth.md`](./docs/auth.md)。
+
+### 防爆破 / 指数退避
+
+登录失败超过 3 次后进入指数退避（`wait = min(900s, 1s × 2^(failures-3))`），期间请求返回 `429 Too Many Requests`（含 `Retry-After` 响应头）；成功登录后自动清零。退避按 **client IP** 与 **username** 双键取较大值，不会因此永久锁定账号（只是延迟，不是封号）。
+
+- 全局开关：`AUTH_LOGIN_THROTTLE_ENABLED`（CONFIG_FIELDS，默认 `true`）
+- 反代后需要 `AUTH_TRUST_FORWARDED_FOR=true` 才会读 `X-Forwarded-For`（`.env` 部署级配置，默认 `false`）
+
+### CLI 逃生通道
+
+拿到服务器 CLI 权限时，可以在**不依赖任何已存凭据**（无需密码、恢复码）的情况下重置密码、解锁退避、关停 TOTP：
+
+```bash
+# 重置密码（不加 --password 则交互式输入，不回显）
+python -m scripts.admin_cli reset-password admin
+
+# 解锁退避（被 429 挡住时使用）
+python -m scripts.admin_cli unlock --all            # 清所有退避行
+python -m scripts.admin_cli unlock --ip 1.2.3.4    # 按 IP 清
+python -m scripts.admin_cli unlock --username admin # 按 username 清
+
+# TOTP 相关（需要先启用，见下文）
+python -m scripts.admin_cli disable-totp admin     # 关停 TOTP（零凭据，逃生口）
+python -m scripts.admin_cli reissue-totp admin     # 重新发放 TOTP secret（打印新 URI）
+
+# 查看用户列表
+python -m scripts.admin_cli list-admin
+```
+
+在 Docker 容器内执行时：
+
+```bash
+docker compose exec app python -m scripts.admin_cli <command>
+```
+
+### 可选 TOTP 二次验证
+
+admin 可在 React SPA 设置页（`/config`）自选启用 RFC 6238 TOTP：
+
+1. 设置页点「启用 TOTP」→ 后端生成 `otpauth://` URI，前端渲染二维码（`qrcode.react`）
+2. 用 Authenticator App（如 Google Authenticator、Authy）扫码
+3. 输入当前 6 位动态码确认 → TOTP 启用
+4. 妥善保存一次性展示的 10 个恢复码（格式 `xxxx-xxxx`）
+
+启用后，登录需要两步：密码 → 6 位动态码（或恢复码，一次性）。不启用则维持纯密码登录，行为不变。
+
+恢复码丢失时，可用 CLI 逃生：`python -m scripts.admin_cli disable-totp admin`，随后即可纯密码登录。
+
+TOTP issuer 标签（显示在 Authenticator 里）通过 `AUTH_TOTP_ISSUER` 环境变量配置（`.env` 部署级），默认回退 `app_name`。
+
+## M5 Modbus 设备采集 / Energy / MQTT + HA Discovery
+
+M5 给后端接入家庭 IoT 生态，新增通用 Modbus 采集链路（首个领域：能耗）、MQTT + Home Assistant Discovery 发布，以及前端侧边栏与 Energy 视图。
+
+### 依赖
+
+后端新增：
+- `pymodbus`：Modbus-TCP 客户端（轮询电表等 slave 设备）
+- `paho-mqtt`：MQTT 客户端（HA Discovery 与 state 发布）
+- `pyyaml`：YAML profile 加载（设备协议声明式描述）
+
+前端新增：
+- `recharts`：Energy 视图走势图
+
+### Modbus 设备采集
+
+采集链路采用两层分离：**YAML profile**（协议知识，随代码走）+ **`modbus_device` 数据库行**（部署/可配置信息）+ **`modbus_reading` 通用读数表**（JSON payload 遥测）。
+
+- **profile**（如 `sdm120.yaml`）描述：读哪些寄存器（FC04 块读）、每个量的 key/unit/device_class/ha_component。纯协议知识，不含 unit_id / friendly_name 等部署项。
+- **`modbus_device` 行**：friendly_name、网关 host/port、Modbus slave `unit_id`（电表 Meter ID，设备面板可改故落 DB）、选用哪个 profile、采样周期、是否启用。
+- **`modbus_reading` 行**：device_id FK、recorded_at、payload（JSON，如 `{"voltage": 230.2, "current": 1.3, ...}`）。
+- 多设备可共享同一 profile（如两块 SDM120 共用 `sdm120` profile，各自独立 unit_id 和 friendly_name）。
+- APScheduler 后台 job 周期轮询所有 `enabled` 设备，更新 `last_poll_at` / `last_poll_ok`。全局开关 `MODBUS_POLLING_ENABLED`（CONFIG_FIELDS）。
+
+**手工命令行试读**（不依赖 DB，最快验证网关连通性）：
+
+```bash
+# 按 profile 解码读一次（验证整套解码链路）
+python -m scripts.modbus_cli read --host <网关IP> --port 502 --unit 1 --profile sdm120
+
+# 手工指定请求内容（first-contact 验证，不依赖 profile）
+python -m scripts.modbus_cli probe --host <网关IP> --port 502 --unit 1 --fc 4 --address 0x0000 --count 2 --decode float32
+```
+
+CLI 工具为受控手工验证而设（设备需接市电），仅暴露读功能码（FC03/04），无写寄存器子命令。
+
+### MQTT + Home Assistant Discovery
+
+后端作为 MQTT 发布方，把 Modbus 设备/工程量以 HA Discovery 协议自动注册为 device/entity：
+
+- 每个 Modbus 设备 = 一个 HA device（`unique_id` 锚定于设备 `uuid`，不随改名变）
+- 各工程量 = sensor entity（device_class/unit 取自 YAML profile）；另有 binary_sensor `online`（取 `last_poll_ok`）
+- 每次轮询成功后推 state topic；连接成功或勾选变更时重发 retained discovery config
+- `POST /api/config/mqtt/test`：试连 broker 并发布一条测试消息（可用 MQTT Explorer 验证链路）
+
+**Config 页配置流程**：
+1. 在 `/config` 的「MQTT」section 填写 broker host/port/username/password，启用 `MQTT_ENABLED`
+2. 点「发送测试消息」确认 broker 链路通
+3. 启用 `HA_DISCOVERY_ENABLED`
+4. 在「Home Assistant Expose」面板勾选要暴露的实体，点「重新发布 discovery」
+5. 在 Home Assistant 确认对应 device/entity 出现
+
+### API 端点（M5 新增）
+
+| 端点 | 用途 |
+| --- | --- |
+| `GET /api/modbus/devices` | 列出 Modbus 设备 |
+| `POST /api/modbus/devices` | 新建设备 |
+| `GET /api/modbus/devices/{uuid}` | 单个设备 |
+| `PATCH /api/modbus/devices/{uuid}` | 修改设备（含 enable/disable）|
+| `DELETE /api/modbus/devices/{uuid}` | 删除设备；有读数时 409 |
+| `GET /api/modbus/devices/{uuid}/metrics` | 该设备 profile 的量目录（key/unit/device_class）|
+| `GET /api/modbus/devices/{uuid}/latest` | 最新一条读数 payload |
+| `GET /api/modbus/devices/{uuid}/readings` | 时间范围读数（start/end/limit），供走势图 |
+| `POST /api/modbus/devices/{uuid}/test` | 即时试读（不落库） |
+| `GET /api/modbus/profiles` | 列出可用 profile 名 + 描述 |
+| `GET /api/expose` | 可暴露实体目录 + 勾选状态 + MQTT/Discovery 状态 |
+| `PUT /api/expose` | 设置逐 key 暴露开关 |
+| `POST /api/expose/republish` | 手动重发 discovery |
+| `POST /api/config/mqtt/test` | 试连 broker 并发布测试消息 |
+
+### 前端视图（M5 新增）
+
+- **侧边栏**：把顶栏改为侧边导航（Home / Records / Energy / Config + 主题切换 + 注销），当前路由高亮，移动端可折叠。
+- **`/energy`（Energy 视图）**：设备 CRUD（新建/编辑/删除，删除有二次确认；有读数时引导改用禁用）；最新读数卡片（字段标签/单位取自 profile metrics）；时间序列走势图（Recharts，支持电压/电流/功率/电能，带时间范围选择）。
+- **Config 页 Accordion**：各大 config section 可独立折叠/展开；「Home Assistant Expose」面板按设备分组勾选可暴露实体、显示 MQTT/Discovery 连接状态、「重新发布 discovery」按钮。
+- SPA 路由新增 `/energy`。
+
+## M6 DSMR 接入 / 电价合同 / 实时电费计算 / HA Energy 反哺
+
+M6 在 M5 IoT 基建之上接入 DSMR 实时智能电表数据，建立通用电价合同层，按每 15 分钟算出实际买卖电费并反哺 HA Energy。
+
+### 依赖
+
+M6 **不新增任何 Python 依赖**，复用 M5 已有的 `httpx`（Tibber GraphQL）、`paho-mqtt`（DSMR 订阅）、`pyyaml`（pricing profile 加载）、`apscheduler`（抓价 job、计费 job）。
+
+### DSMR 实时电表接入
+
+订阅 DSMR Reader 的 `dsmr/json` topic（每秒一帧完整 telegram），整帧存为 JSON blob、按 `dsmr_sample_interval_s`（默认 10 秒）降采样落 `dsmr_reading`（`source_id` 幂等去重）。`dsmr_ingest_enabled`（默认 false，opt-in）。
+
+### 电价合同层
+
+- **YAML profile 定结构**（仓库内，不放数值）：`manual.yaml`（固定/双费率：buy_normal/dal、sell_normal/dal、energy_tax、ode、固定费、heffingskorting）；`tibber.yaml`（动态：source=tibber_api，energy_tax、sell_adjust）
+- **`EnergyContract` + `EnergyContractVersion`**（UI 填数值）：改价 = 加新版本行（带 `effective_from`），旧版本保留（审计链）；一次只有一个 active 合同
+- **price strategy**：`manual` 用双费率常数（`buy = energy_buy_档 + energy_tax`，`sell = sell_档`）；`tibber` 用 `tibber_price.total` 作买价（已含税，demo 确认 `total=energy+tax`），`total − energy_tax − sell_adjust` 作卖价（卖价残差 `sell_adjust` 默认 0，待真实账单核定）
+
+### 每 15 分钟计量电费（不可变）
+
+APScheduler 1 分钟 tick，取每个闭合 15 分钟窗口的 DSMR 寄存器差值（`delivered_1/2`，`returned_1/2`；`_1`=dal/低，`_2`=normal/高，NL 惯例）× 当时合同版本的 strategy 出价，upsert `energy_cost_period`（快照当时价 + `contract_version_id`）。缺价/缺数据时标 `degraded`。`POST /api/energy/costs/recompute` 显式重算。
+
+日/月/年汇总 = Σnet + 固定费（network_fee + management_fee 按月→天 × 天数）- heffingskorting（按年→天 × 天数），读时计算、不落表。能源税 `energy_tax` 参考值约 0.1108 EUR/kWh（2026 第一档含 VAT，待真实账单核定；该值由 UI 填入合同版本，YAML profile 仅声明字段 unit，代码无写死默认数值）。
+
+### Tibber 动态电价
+
+`app/integrations/tibber/client.py` httpx POST GraphQL（`priceInfoRange(QUARTER_HOURLY, first=96)`），解析 `startsAt`/`total`/`energy`/`tax`/`level`，按 `starts_at` upsert `tibber_price`（幂等）。启动 + 每小时抓取今明两天 15 分钟价、幂等 upsert（hourly trigger，确保每日刷新且可补重试）；仅当 active 合同 kind=tibber 且 `tibber_api_token` 存在时运行。`POST /api/energy/tibber/test` 试连三态（success 带当前价 / config-error / failed）。
+
+### 反哺 Home Assistant Energy
+
+`_energy_cost_provider` 向 expose 框架注册 4 个实体：`buy_price_now`、`sell_price_now`（€/kWh sensor）、`import_cost_total`、`export_revenue_total`（`total_increasing` monetary，可直接挂 HA Energy 仪表盘）。默认未勾选，在 Expose 面板启用。
+
+### API 端点（M6 新增）
+
+| 端点 | 用途 |
+| --- | --- |
+| `GET /api/energy/contracts` | 列出合同 + active 标记 |
+| `POST /api/energy/contracts` | 新建合同（kind + 首版本值，按 profile 校验）|
+| `GET /api/energy/contracts/{id}` | 单个合同 + 版本历史 |
+| `PATCH /api/energy/contracts/{id}` | 改名 / 激活 |
+| `POST /api/energy/contracts/{id}/versions` | 加新版本（改价，带生效日期）|
+| `GET /api/energy/profiles` | 列出 pricing profile 结构（前端按它渲染表单）|
+| `GET /api/energy/prices` | 区间价格点（曲线）|
+| `GET /api/energy/costs` | 区间 `energy_cost_period`（走势/明细）|
+| `GET /api/energy/costs/summary` | 区间汇总（计量电费 + 固定费 − 抵扣）|
+| `POST /api/energy/costs/recompute` | 幂等重算 |
+| `GET /api/energy/dsmr/latest` | 最新 `dsmr_reading` |
+| `POST /api/energy/tibber/test` | 试连 Tibber + 拉当前价，三态 |
+
+DSMR/Tibber 标量配置复用现有 `GET/PUT /api/config`（新增 `dsmr_ingest_enabled`、`dsmr_mqtt_topic`、`dsmr_sample_interval_s`、`tibber_api_token`（secret）、`tibber_home_id`）。
+
+### 前端视图（M6 新增，并入 Energy 视图）
+
+- **Contracts Tab**：合同列表 + 新建/编辑（表单按 `/api/energy/profiles` 结构渲染，不 hardcode 字段）+ 激活 + 改价加版本 + 版本历史只读。
+- **Prices Tab**：15 分钟价格曲线（tibber 动态或 manual 档位），复用 Recharts。
+- **Costs Tab**：费用走势/明细 + 汇总卡片（含固定费/抵扣）。
+- **Config 页 Tibber 测试**：三态（success/config-error/failed）。
+
 ## Config 持久化

 当前 config 页面不会把修改写回 `.env`。
@@ -253,6 +457,11 @@ React SPA 主要页面路由（客户端路由，均由 FastAPI fallback 到 `in
 - SMTP 基础配置
 - TickTick OAuth 配置
 - Home Assistant 配置
+- MQTT broker 配置（`MQTT_ENABLED`、`MQTT_BROKER_HOST/PORT/USERNAME/PASSWORD`、`MQTT_TLS_ENABLED`）
+- Home Assistant Discovery 配置（`HA_DISCOVERY_ENABLED`、`HA_DISCOVERY_PREFIX`）
+- Modbus 采集配置（`MODBUS_POLLING_ENABLED`）
+- DSMR 接入配置（`DSMR_INGEST_ENABLED`、`DSMR_MQTT_TOPIC`、`DSMR_SAMPLE_INTERVAL_S`）
+- Tibber 凭据（`TIBBER_API_TOKEN`（secret）、`TIBBER_HOME_ID`）

 其中 SMTP password 与其他 secret 字段一致：

@@ -6,10 +6,20 @@ from sqlalchemy import engine_from_config, pool
 from app.config import get_settings
 from app.db import Base
 from app.models.config import AppConfigEntry  # noqa: F401
-from app.models.auth import AuthSession, AuthUser  # noqa: F401
+from app.models.auth import AuthSession, AuthUser, RecoveryCode  # noqa: F401
+from app.models.auth_throttle import LoginThrottle  # noqa: F401
 from app.models.public_ip import PublicIPHistory, PublicIPState  # noqa: F401
 from app.models.location import Location  # noqa: F401
 from app.models.poo import PooRecord  # noqa: F401
+from app.models.modbus import ModbusDevice, ModbusReading  # noqa: F401
+from app.models.expose import ExposedEntityToggle  # noqa: F401
+from app.models.energy import (  # noqa: F401
+    DsmrReading,
+    EnergyContract,
+    EnergyContractVersion,
+    TibberPrice,
+    EnergyCostPeriod,
+)

 config = context.config

@@ -0,0 +1,43 @@
+"""add auth_login_throttle table for exponential back-off throttling
+
+Revision ID: 20260621_07_auth_login_throttle
+Revises: 20260611_06_merge_location_poo_tables
+Create Date: 2026-06-21 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision: str = "20260621_07_auth_login_throttle"
+down_revision: Union[str, None] = "20260611_06_merge_location_poo_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "auth_login_throttle",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("key", sa.String(length=255), nullable=False),
+        sa.Column("scope", sa.String(length=16), nullable=False),
+        sa.Column("failures", sa.Integer(), nullable=False),
+        sa.Column("first_failed_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("last_failed_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("next_allowed_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("scope", "key", name="uq_auth_login_throttle_scope_key"),
+    )
+    op.create_index(
+        "ix_auth_login_throttle_scope_key",
+        "auth_login_throttle",
+        ["scope", "key"],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_auth_login_throttle_scope_key", table_name="auth_login_throttle")
+    op.drop_table("auth_login_throttle")
@@ -0,0 +1,61 @@
+"""add TOTP fields to auth_users and create auth_recovery_code table
+
+Revision ID: 20260621_08_totp
+Revises: 20260621_07_auth_login_throttle
+Create Date: 2026-06-21 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision: str = "20260621_08_totp"
+down_revision: Union[str, None] = "20260621_07_auth_login_throttle"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Add totp_secret (nullable) to auth_users — existing rows get NULL, which is correct.
+    op.add_column("auth_users", sa.Column("totp_secret", sa.String(length=64), nullable=True))
+    # Add totp_enabled (NOT NULL) with server_default="0" so existing rows default to false.
+    op.add_column(
+        "auth_users",
+        sa.Column(
+            "totp_enabled",
+            sa.Boolean(),
+            nullable=False,
+            server_default="0",
+        ),
+    )
+
+    # Create auth_recovery_code table for one-time TOTP recovery codes.
+    op.create_table(
+        "auth_recovery_code",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("user_id", sa.Integer(), nullable=False),
+        sa.Column("code_hash", sa.String(length=255), nullable=False),
+        sa.Column("used_at", sa.DateTime(timezone=True), nullable=True),
+        sa.ForeignKeyConstraint(["user_id"], ["auth_users.id"]),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        op.f("ix_auth_recovery_code_user_id"),
+        "auth_recovery_code",
+        ["user_id"],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    # Drop auth_recovery_code table first (has FK to auth_users).
+    op.drop_index(op.f("ix_auth_recovery_code_user_id"), table_name="auth_recovery_code")
+    op.drop_table("auth_recovery_code")
+
+    # Drop the two TOTP columns from auth_users.
+    # Use batch_alter_table for SQLite compatibility (alembic's portable column-drop path).
+    with op.batch_alter_table("auth_users") as batch_op:
+        batch_op.drop_column("totp_enabled")
+        batch_op.drop_column("totp_secret")
@@ -0,0 +1,81 @@
+"""add modbus_device and modbus_reading tables
+
+Revision ID: 20260622_09_modbus_tables
+Revises: 20260621_08_totp
+Create Date: 2026-06-22 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision: str = "20260622_09_modbus_tables"
+down_revision: Union[str, None] = "20260621_08_totp"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # modbus_device — deployment/configurable metadata for each polled device.
+    op.create_table(
+        "modbus_device",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("uuid", sa.String(length=36), nullable=False),
+        sa.Column("friendly_name", sa.String(length=255), nullable=False),
+        sa.Column("transport", sa.String(length=16), nullable=False),
+        sa.Column("host", sa.String(length=255), nullable=False),
+        sa.Column("port", sa.Integer(), nullable=False),
+        sa.Column("unit_id", sa.Integer(), nullable=False),
+        sa.Column("profile", sa.String(length=64), nullable=False),
+        sa.Column("poll_interval_s", sa.Integer(), nullable=False),
+        sa.Column("enabled", sa.Boolean(), nullable=False),
+        sa.Column("last_poll_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("last_poll_ok", sa.Boolean(), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("uuid", name="uq_modbus_device_uuid"),
+    )
+
+    # modbus_reading — generic telemetry, one row per device per poll cycle.
+    op.create_table(
+        "modbus_reading",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("device_id", sa.Integer(), nullable=False),
+        sa.Column("recorded_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("payload", sa.JSON(), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["device_id"],
+            ["modbus_device.id"],
+            ondelete="RESTRICT",
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    # Individual index on recorded_at (from the ORM-level index=True).
+    op.create_index(
+        "ix_modbus_reading_recorded_at",
+        "modbus_reading",
+        ["recorded_at"],
+        unique=False,
+    )
+
+    # Composite index for efficient time-range queries per device.
+    op.create_index(
+        "ix_modbus_reading_device_recorded",
+        "modbus_reading",
+        ["device_id", "recorded_at"],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    # Drop the reading table first (it has a FK referencing modbus_device).
+    op.drop_index("ix_modbus_reading_device_recorded", table_name="modbus_reading")
+    op.drop_index("ix_modbus_reading_recorded_at", table_name="modbus_reading")
+    op.drop_table("modbus_reading")
+
+    # Drop the device table.
+    op.drop_table("modbus_device")
@@ -0,0 +1,44 @@
+"""add exposed_entity_toggle table
+
+Revision ID: 20260622_10_exposed_entities
+Revises: 20260622_09_modbus_tables
+Create Date: 2026-06-22 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision: str = "20260622_10_exposed_entities"
+down_revision: Union[str, None] = "20260622_09_modbus_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # exposed_entity_toggle — per-entity on/off switch for MQTT / HA Discovery.
+    op.create_table(
+        "exposed_entity_toggle",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("key", sa.String(length=255), nullable=False),
+        sa.Column("enabled", sa.Boolean(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("key", name="uq_exposed_entity_toggle_key"),
+    )
+
+    # Index on key for fast single-key lookups (toggle by key).
+    op.create_index(
+        "ix_exposed_entity_toggle_key",
+        "exposed_entity_toggle",
+        ["key"],
+        unique=True,
+    )
+
+
+def downgrade() -> None:
+    # Drop index then table — only removes what this revision created.
+    op.drop_index("ix_exposed_entity_toggle_key", table_name="exposed_entity_toggle")
+    op.drop_table("exposed_entity_toggle")
@@ -0,0 +1,132 @@
+"""add energy pricing and DSMR metering tables
+
+Revision ID: 20260623_11_energy_tables
+Revises: 20260622_10_exposed_entities
+Create Date: 2026-06-23 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision: str = "20260623_11_energy_tables"
+down_revision: Union[str, None] = "20260622_10_exposed_entities"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # dsmr_reading — raw DSMR telegram blobs (10-second down-sampled).
+    # No device table: single P1 smart meter; a ``source`` column can be added later
+    # if a second meter is introduced.
+    op.create_table(
+        "dsmr_reading",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("recorded_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("source_id", sa.Integer(), nullable=True),
+        sa.Column("payload", sa.JSON(), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("source_id", name="uq_dsmr_reading_source_id"),
+    )
+    op.create_index(
+        "ix_dsmr_reading_recorded_at",
+        "dsmr_reading",
+        ["recorded_at"],
+        unique=False,
+    )
+
+    # energy_contract — contract head (manual or tibber, one active at a time).
+    op.create_table(
+        "energy_contract",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("kind", sa.String(length=32), nullable=False),
+        sa.Column("active", sa.Boolean(), nullable=False),
+        sa.Column("currency", sa.String(length=8), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    # energy_contract_version — versioned pricing values; append-only for auditability.
+    # Must be created after energy_contract because of the FK dependency.
+    op.create_table(
+        "energy_contract_version",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("contract_id", sa.Integer(), nullable=False),
+        sa.Column("effective_from", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("effective_to", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("values", sa.JSON(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["contract_id"],
+            ["energy_contract.id"],
+            ondelete="RESTRICT",
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    # tibber_price — cached Tibber 15-minute spot prices (immutable once fetched).
+    op.create_table(
+        "tibber_price",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("starts_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("resolution", sa.String(length=32), nullable=False),
+        sa.Column("energy", sa.Float(), nullable=False),
+        sa.Column("tax", sa.Float(), nullable=False),
+        sa.Column("total", sa.Float(), nullable=False),
+        sa.Column("level", sa.String(length=32), nullable=True),
+        sa.Column("currency", sa.String(length=8), nullable=False),
+        sa.Column("fetched_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("starts_at", name="uq_tibber_price_starts_at"),
+    )
+
+    # energy_cost_period — computed 15-minute billing periods (immutable snapshot).
+    # Must be created after energy_contract_version because of the FK dependency.
+    op.create_table(
+        "energy_cost_period",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("period_start", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("d1_kwh", sa.Float(), nullable=False),
+        sa.Column("d2_kwh", sa.Float(), nullable=False),
+        sa.Column("r1_kwh", sa.Float(), nullable=False),
+        sa.Column("r2_kwh", sa.Float(), nullable=False),
+        sa.Column("import_cost", sa.Float(), nullable=False),
+        sa.Column("export_revenue", sa.Float(), nullable=False),
+        sa.Column("net_cost", sa.Float(), nullable=False),
+        sa.Column("currency", sa.String(length=8), nullable=False),
+        sa.Column("pricing", sa.JSON(), nullable=False),
+        sa.Column("contract_version_id", sa.Integer(), nullable=True),
+        sa.Column("degraded", sa.Boolean(), nullable=False),
+        sa.Column("computed_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["contract_version_id"],
+            ["energy_contract_version.id"],
+            ondelete="RESTRICT",
+        ),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("period_start", name="uq_energy_cost_period_period_start"),
+    )
+
+
+def downgrade() -> None:
+    # Drop tables in reverse dependency order: tables with FKs first.
+
+    # energy_cost_period has a FK to energy_contract_version — drop it first.
+    op.drop_table("energy_cost_period")
+
+    # tibber_price has no FK dependencies on our new tables.
+    op.drop_table("tibber_price")
+
+    # energy_contract_version has a FK to energy_contract — drop it before energy_contract.
+    op.drop_table("energy_contract_version")
+
+    # energy_contract has no FK dependencies on our new tables.
+    op.drop_table("energy_contract")
+
+    # dsmr_reading has no FK dependencies.
+    op.drop_index("ix_dsmr_reading_recorded_at", table_name="dsmr_reading")
+    op.drop_table("dsmr_reading")
@@ -0,0 +1,58 @@
+"""decouple dsmr_reading from the telegram id
+
+The DSMR Reader's own ``id`` field is auto-incrementing but is known to overflow
+and require a manual reset to zero (a long-standing DSMR firmware quirk).  If we
+keep a UNIQUE constraint on ``source_id`` (the telegram id) and use it for
+idempotency, an overflow/reset would make legitimately-new telegrams collide with
+old ids and be silently dropped as "duplicates" — data loss.
+
+This migration removes that coupling:
+
+- Drops the UNIQUE constraint on ``source_id`` (the column is kept as a plain,
+  nullable reference value; it is no longer relied upon for uniqueness/dedup).
+- Makes ``recorded_at`` (the telegram timestamp) UNIQUE instead — a single P1
+  meter emits one telegram per timestamp, so this is a robust, telegram-id-
+  independent idempotency key.  The table's own autoincrement ``id`` PK remains
+  the stable internal identity.
+
+Revision ID: 20260624_12_dsmr_decouple_telegram_id
+Revises: 20260623_11_energy_tables
+Create Date: 2026-06-24 00:00:00.000000
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+
+
+revision: str = "20260624_12_dsmr_decouple_telegram_id"
+down_revision: Union[str, None] = "20260623_11_energy_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # SQLite cannot ALTER away a constraint in place, so recreate the table via
+    # Alembic's batch mode.  The table is recreated and rows are copied; existing
+    # data (if any) is preserved.  recorded_at must be unique for this to succeed
+    # — a single meter never emits two telegrams at the exact same timestamp.
+    with op.batch_alter_table("dsmr_reading", schema=None) as batch_op:
+        # Old non-unique index on recorded_at is replaced by the unique constraint.
+        batch_op.drop_index("ix_dsmr_reading_recorded_at")
+        # Telegram id is no longer a uniqueness/idempotency key.
+        batch_op.drop_constraint("uq_dsmr_reading_source_id", type_="unique")
+        # Timestamp becomes the telegram-id-independent dedup key.
+        batch_op.create_unique_constraint(
+            "uq_dsmr_reading_recorded_at", ["recorded_at"]
+        )
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("dsmr_reading", schema=None) as batch_op:
+        batch_op.drop_constraint("uq_dsmr_reading_recorded_at", type_="unique")
+        batch_op.create_unique_constraint(
+            "uq_dsmr_reading_source_id", ["source_id"]
+        )
+        batch_op.create_index(
+            "ix_dsmr_reading_recorded_at", ["recorded_at"], unique=False
+        )
@@ -0,0 +1,238 @@
+"""add meter table and energy_cost_period.meter_id
+
+Introduces the ``meter`` table (one row per physical meter installation epoch)
+and a nullable FK column ``energy_cost_period.meter_id`` that attributes each
+billing period to a specific physical meter.
+
+**Backfill logic (§3.7 of the M7 design doc)**:
+
+If the database already contains any ``dsmr_reading`` or
+``energy_cost_period`` rows, one initial ``meter`` row is created:
+
+  label      = "Initial meter"
+  commodity  = "electricity"
+  started_at = earliest dsmr_reading.recorded_at
+               (or, if none, earliest energy_cost_period.period_start,
+                or, if still none, the migration timestamp)
+  ended_at   = NULL  (still active)
+  reason     = "initial"
+
+All existing ``energy_cost_period`` rows are then back-filled with that
+initial meter's id.
+
+**Idempotency**: the backfill is guarded with a check for any existing
+``meter`` row whose ``reason = 'initial'`` and ``commodity = 'electricity'``
+and ``ended_at IS NULL``, so repeating the upgrade does not create duplicate
+meters or overwrite already-filled meter_id values.
+
+**Audit (on-non-degraded periods only)**: after backfilling, the number of
+non-degraded ``energy_cost_period`` rows with ``meter_id IS NULL`` must be
+zero; if it is not, the migration raises a ``RuntimeError`` and rolls back.
+
+**Data safety**: this migration is additive only — no existing rows are
+deleted or overwritten; it only creates a new table, adds a nullable column,
+and back-fills that column.
+
+Revision ID: 20260625_13_meter_table
+Revises: 20260624_12_dsmr_decouple_telegram_id
+Create Date: 2026-06-25 00:00:00.000000
+"""
+
+from datetime import datetime, timezone
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "20260625_13_meter_table"
+down_revision: Union[str, None] = "20260624_12_dsmr_decouple_telegram_id"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ------------------------------------------------------------------ #
+    # 1. Create the meter table.                                          #
+    # ------------------------------------------------------------------ #
+    op.create_table(
+        "meter",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("label", sa.String(length=255), nullable=False),
+        sa.Column("commodity", sa.String(length=32), nullable=False),
+        sa.Column("started_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("ended_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("reason", sa.String(length=64), nullable=False),
+        sa.Column("note", sa.String(length=1024), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    # ------------------------------------------------------------------ #
+    # 2. Add meter_id column to energy_cost_period (nullable FK).         #
+    # ------------------------------------------------------------------ #
+    with op.batch_alter_table("energy_cost_period", schema=None) as batch_op:
+        batch_op.add_column(
+            sa.Column("meter_id", sa.Integer(), nullable=True)
+        )
+        batch_op.create_foreign_key(
+            "fk_energy_cost_period_meter_id",
+            "meter",
+            ["meter_id"],
+            ["id"],
+            ondelete="RESTRICT",
+        )
+
+    # ------------------------------------------------------------------ #
+    # 3. Backfill initial meter (idempotent).                             #
+    # ------------------------------------------------------------------ #
+    conn = op.get_bind()
+
+    # Check if there is already an initial meter (idempotency guard).
+    existing_initial = conn.execute(
+        sa.text(
+            "SELECT id FROM meter "
+            "WHERE reason = 'initial' AND commodity = 'electricity' AND ended_at IS NULL "
+            "LIMIT 1"
+        )
+    ).fetchone()
+
+    if existing_initial is not None:
+        # Already backfilled — nothing to do.
+        return
+
+    # Determine whether there is any historical data to create a meter for.
+    has_readings = conn.execute(
+        sa.text("SELECT 1 FROM dsmr_reading LIMIT 1")
+    ).fetchone()
+    has_periods = conn.execute(
+        sa.text("SELECT 1 FROM energy_cost_period LIMIT 1")
+    ).fetchone()
+
+    if not has_readings and not has_periods:
+        # Empty database: no historical data, so no initial meter is needed.
+        # meter_id will remain NULL on any future rows until T02 service layer
+        # starts populating it.
+        return
+
+    # Determine started_at: earliest dsmr_reading.recorded_at, falling back to
+    # earliest energy_cost_period.period_start, and finally to now().
+    earliest_reading_row = conn.execute(
+        sa.text("SELECT MIN(recorded_at) AS ts FROM dsmr_reading")
+    ).fetchone()
+    earliest_period_row = conn.execute(
+        sa.text("SELECT MIN(period_start) AS ts FROM energy_cost_period")
+    ).fetchone()
+
+    started_at_value: datetime | None = None
+    if earliest_reading_row and earliest_reading_row[0] is not None:
+        # SQLite returns ISO strings for datetime columns; parse to datetime.
+        raw = earliest_reading_row[0]
+        started_at_value = _parse_sqlite_datetime(raw)
+    if started_at_value is None and earliest_period_row and earliest_period_row[0] is not None:
+        raw = earliest_period_row[0]
+        started_at_value = _parse_sqlite_datetime(raw)
+    if started_at_value is None:
+        started_at_value = datetime.now(tz=timezone.utc)
+
+    now_utc = datetime.now(tz=timezone.utc)
+
+    # Insert the initial meter row.
+    conn.execute(
+        sa.text(
+            "INSERT INTO meter (label, commodity, started_at, ended_at, reason, note, created_at) "
+            "VALUES (:label, :commodity, :started_at, NULL, :reason, NULL, :created_at)"
+        ),
+        {
+            "label": "Initial meter",
+            "commodity": "electricity",
+            "started_at": _iso(started_at_value),
+            "reason": "initial",
+            "created_at": _iso(now_utc),
+        },
+    )
+
+    # Retrieve the newly created meter id.
+    meter_row = conn.execute(
+        sa.text(
+            "SELECT id FROM meter "
+            "WHERE reason = 'initial' AND commodity = 'electricity' AND ended_at IS NULL "
+            "LIMIT 1"
+        )
+    ).fetchone()
+    assert meter_row is not None, "Initial meter row not found after insert"
+    meter_id: int = meter_row[0]
+
+    # Back-fill all existing energy_cost_period rows that have meter_id IS NULL.
+    conn.execute(
+        sa.text(
+            "UPDATE energy_cost_period SET meter_id = :mid WHERE meter_id IS NULL"
+        ),
+        {"mid": meter_id},
+    )
+
+    # ------------------------------------------------------------------ #
+    # 4. Audit: verify all non-degraded periods have a meter_id.          #
+    # ------------------------------------------------------------------ #
+    unmatched_row = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM energy_cost_period "
+            "WHERE meter_id IS NULL AND degraded = 0"
+        )
+    ).fetchone()
+    unmatched_count: int = unmatched_row[0] if unmatched_row else 0
+
+    if unmatched_count != 0:
+        raise RuntimeError(
+            f"Meter backfill audit failed: {unmatched_count} non-degraded "
+            "energy_cost_period row(s) still have meter_id IS NULL after backfill. "
+            "Migration aborted to protect data integrity."
+        )
+
+
+def downgrade() -> None:
+    # Remove the FK column from energy_cost_period first (references meter).
+    with op.batch_alter_table("energy_cost_period", schema=None) as batch_op:
+        batch_op.drop_constraint("fk_energy_cost_period_meter_id", type_="foreignkey")
+        batch_op.drop_column("meter_id")
+
+    # Drop the meter table.
+    op.drop_table("meter")
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _parse_sqlite_datetime(value: str | datetime) -> datetime:
+    """Parse a SQLite datetime value into an aware UTC datetime.
+
+    SQLite stores datetimes as ISO 8601 strings.  SQLAlchemy may return them
+    as plain strings or as naive datetimes (no tzinfo) depending on the driver
+    and column declaration.  This helper normalises both forms to an aware UTC
+    ``datetime``.
+    """
+    if isinstance(value, datetime):
+        if value.tzinfo is None:
+            return value.replace(tzinfo=timezone.utc)
+        return value
+    # String form — strip trailing Z or +00:00 variants, then attach UTC.
+    s = str(value).strip()
+    for suffix in ("+00:00", "Z", " UTC"):
+        if s.endswith(suffix):
+            s = s[: -len(suffix)]
+    # SQLite uses space as the T separator in some formats.
+    s = s.replace(" ", "T")
+    try:
+        dt = datetime.fromisoformat(s)
+    except ValueError:
+        # Fallback: strip subseconds if present to handle unusual formats.
+        dt = datetime.strptime(s[:19], "%Y-%m-%dT%H:%M:%S")
+    return dt.replace(tzinfo=timezone.utc)
+
+
+def _iso(dt: datetime) -> str:
+    """Serialise a datetime to an ISO 8601 string for SQLite storage."""
+    if dt.tzinfo is not None:
+        dt = dt.astimezone(timezone.utc).replace(tzinfo=None)
+    return dt.strftime("%Y-%m-%dT%H:%M:%S")
@@ -0,0 +1,104 @@
+"""add uuid column to meter table
+
+Adds a stable ``uuid`` (UUID v4 string) column to the ``meter`` table so that
+each meter epoch has a durable identity anchor suitable for use as an HA
+Discovery ``unique_id``.
+
+**Migration strategy (SQLite-safe)**:
+
+SQLite does not support adding a NOT NULL + UNIQUE column to a non-empty table
+in a single ``ALTER TABLE ADD COLUMN`` statement (adding a NOT NULL column
+without a default value is rejected if the table already has rows).  The
+safe approach used here is:
+
+  1. Add ``uuid`` as a **nullable** column (SQLite allows this).
+  2. **Back-fill** every existing ``meter`` row with a distinct ``str(uuid4())``
+     value.  Each row gets its *own* random UUID — not a shared value — so the
+     subsequent UNIQUE constraint is satisfied.
+  3. Use ``batch_alter_table`` (which re-creates the table under the hood in
+     SQLite) to alter the column to ``NOT NULL`` and add a UNIQUE constraint.
+
+**Idempotency**: only rows where ``uuid IS NULL`` are back-filled; rows that
+already have a uuid (e.g. from a repeated upgrade after a partial failure) are
+left untouched.
+
+**Audit**: after back-fill, the count of rows with ``uuid IS NULL`` must be
+exactly zero; if not, the migration raises ``RuntimeError`` and rolls back.
+
+**Data safety**: this migration is additive only — no existing rows are deleted
+or overwritten; it only adds a new column and fills it in.
+
+Revision ID: 20260625_14_meter_uuid
+Revises: 20260625_13_meter_table
+Create Date: 2026-06-25 00:00:00.000000
+"""
+
+import uuid as _uuid
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "20260625_14_meter_uuid"
+down_revision: Union[str, None] = "20260625_13_meter_table"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # ------------------------------------------------------------------ #
+    # 1. Add uuid as a nullable column.                                    #
+    # ------------------------------------------------------------------ #
+    with op.batch_alter_table("meter", schema=None) as batch_op:
+        batch_op.add_column(
+            sa.Column("uuid", sa.String(length=36), nullable=True)
+        )
+
+    # ------------------------------------------------------------------ #
+    # 2. Back-fill: assign a distinct UUID to every row that has           #
+    #    uuid IS NULL.  Each row gets its own random value so that the     #
+    #    subsequent UNIQUE constraint is satisfied.                        #
+    # ------------------------------------------------------------------ #
+    rows = conn.execute(sa.text("SELECT id FROM meter WHERE uuid IS NULL")).fetchall()
+    for (meter_id,) in rows:
+        new_uuid = str(_uuid.uuid4())
+        conn.execute(
+            sa.text("UPDATE meter SET uuid = :uuid WHERE id = :mid"),
+            {"uuid": new_uuid, "mid": meter_id},
+        )
+
+    # ------------------------------------------------------------------ #
+    # 3. Audit: verify no rows remain with uuid IS NULL.                   #
+    # ------------------------------------------------------------------ #
+    null_count_row = conn.execute(
+        sa.text("SELECT COUNT(*) FROM meter WHERE uuid IS NULL")
+    ).fetchone()
+    null_count: int = null_count_row[0] if null_count_row else 0
+
+    if null_count != 0:
+        raise RuntimeError(
+            f"meter.uuid back-fill audit failed: {null_count} meter row(s) still have "
+            "uuid IS NULL after back-fill.  Migration aborted to protect data integrity."
+        )
+
+    # ------------------------------------------------------------------ #
+    # 4. Alter column to NOT NULL + UNIQUE (requires batch on SQLite).     #
+    #    batch_alter_table re-creates the table, so the UNIQUE constraint  #
+    #    and NOT NULL are applied atomically.                              #
+    # ------------------------------------------------------------------ #
+    with op.batch_alter_table("meter", schema=None) as batch_op:
+        batch_op.alter_column(
+            "uuid",
+            existing_type=sa.String(length=36),
+            nullable=False,
+        )
+        batch_op.create_unique_constraint("uq_meter_uuid", ["uuid"])
+
+
+def downgrade() -> None:
+    # Drop the UNIQUE constraint and the uuid column (batch on SQLite).
+    with op.batch_alter_table("meter", schema=None) as batch_op:
+        batch_op.drop_constraint("uq_meter_uuid", type_="unique")
+        batch_op.drop_column("uuid")
@@ -9,12 +9,14 @@ from sqlalchemy.orm import Session
 from app.api.routes.api.deps import require_csrf, require_session
 from app.config import Settings, get_settings
 from app.dependencies import get_app_settings, get_db
+from app.integrations.mqtt import MQTT_SETTINGS_KEYS, mqtt_manager
 from app.schemas.config import (
    ConfigField,
    ConfigResponse,
    ConfigSection,
    ConfigUpdateRequest,
    ConfigUpdateResponse,
+    MqttTestResponse,
    SmtpTestResponse,
 )
 from app.services.auth import AuthenticatedSession
@@ -58,7 +60,12 @@ def put_config(

    - Blank secret value keeps the existing stored value (no change).
    - Invalid values return 422 and nothing is written to the database.
+    - If MQTT-related settings changed, the MQTT client reconnects automatically.
    """
+    # Detect whether any MQTT-related key is being submitted (non-secret change
+    # or non-blank secret change) so we know to reconnect after saving.
+    mqtt_keys_submitted = any(k.lower() in MQTT_SETTINGS_KEYS for k in body.updates)
+
    try:
        save_config_updates(db, body.updates, settings)
    except ConfigSaveError as exc:
@@ -68,8 +75,23 @@ def put_config(
            detail="invalid config submission",
        ) from exc

-    # Re-read settings after save (save_config_updates clears the settings cache)
-    refreshed_settings = get_settings()
+    # Re-read settings after save (save_config_updates clears the settings cache).
+    # Use build_runtime_settings so the reconnect picks up DB-stored values, not
+    # just the bootstrap env (otherwise a broker configured via the UI is ignored).
+    from app.services.config_page import build_runtime_settings
+    refreshed_settings = build_runtime_settings(db, get_settings())
+
+    # Reconnect MQTT client if any MQTT setting was updated.
+    if mqtt_keys_submitted:
+        logger.info("MQTT settings changed — triggering reconnect.")
+        mqtt_manager.reconnect(refreshed_settings)
+
+    # Re-apply the DSMR subscription so enabling/disabling DSMR ingest (or changing
+    # its topic / sample interval) takes effect immediately, without an app restart.
+    # Done after any MQTT reconnect so it operates on the current client.
+    from app.services.dsmr_ingest import apply_dsmr_subscription
+    apply_dsmr_subscription(refreshed_settings)
+
    sections_raw = build_config_sections(db, refreshed_settings)
    return ConfigUpdateResponse(sections=_sections_from_raw(sections_raw))

@@ -117,3 +139,174 @@ def post_smtp_test(
        status_code=status.HTTP_200_OK,
        content={"result": "success", "message": "Test email sent successfully."},
    )
+
+
+# ---------------------------------------------------------------------------
+# POST /api/config/mqtt/test — M5-T10
+# ---------------------------------------------------------------------------
+
+class _MqttConfigurationError(ValueError):
+    """Raised when MQTT settings are incomplete or disabled."""
+
+
+class _MqttConnectionError(RuntimeError):
+    """Raised when MQTT broker connection or publish fails."""
+
+
+@router.post(
+    "/config/mqtt/test",
+    responses={
+        200: {"model": MqttTestResponse},
+        400: {"model": MqttTestResponse},
+        502: {"model": MqttTestResponse},
+    },
+)
+def post_mqtt_test(
+    settings: Settings = Depends(get_app_settings),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> JSONResponse:
+    """
+    Test MQTT broker connectivity by attempting to connect and publishing a
+    test message to ``<ha_discovery_prefix>/home-automation/test``.
+
+    The message is visible in MQTT Explorer (or any subscriber) so users can
+    confirm the full broker publish path is working.
+
+    Three possible outcomes:
+    - 200 { "result": "success", "message": ... }
+    - 400 { "result": "config-error", "message": ... }   (not configured)
+    - 502 { "result": "failed", "message": ... }          (connection/publish error)
+
+    MQTT credentials are never echoed in the response.
+    """
+    try:
+        _run_mqtt_test(settings)
+    except _MqttConfigurationError as exc:
+        logger.warning("MQTT test rejected due to configuration: %s", exc)
+        return JSONResponse(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            content={"result": "config-error", "message": str(exc)},
+        )
+    except _MqttConnectionError as exc:
+        logger.warning("MQTT test connection/publish failed: %s", exc)
+        return JSONResponse(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            content={"result": "failed", "message": str(exc)},
+        )
+
+    return JSONResponse(
+        status_code=status.HTTP_200_OK,
+        content={
+            "result": "success",
+            "message": (
+                f"Test message published to "
+                f"{settings.ha_discovery_prefix}/home-automation/test."
+            ),
+        },
+    )
+
+
+def _run_mqtt_test(settings: Settings) -> None:
+    """Attempt a transient MQTT connection and publish a test message.
+
+    Raises
+    ------
+    _MqttConfigurationError
+        When MQTT is not enabled or broker host is not configured.
+    _MqttConnectionError
+        When the broker is unreachable or the publish fails.
+    """
+    import socket
+
+    import paho.mqtt.client as mqtt
+
+    if not settings.mqtt_broker_host:
+        raise _MqttConfigurationError("MQTT broker host is not configured.")
+
+    test_topic = f"{settings.ha_discovery_prefix}/home-automation/test"
+    test_payload = '{"source": "home-automation", "event": "mqtt_test"}'
+
+    connected_event = __import__("threading").Event()
+    published_event = __import__("threading").Event()
+    connect_error: list[str] = []
+
+    client = mqtt.Client(
+        callback_api_version=mqtt.CallbackAPIVersion.VERSION2,
+        client_id="home-automation-test",
+    )
+
+    def _on_connect(
+        _client: mqtt.Client,
+        _userdata: object,
+        _flags: mqtt.ConnectFlags,
+        reason_code: mqtt.ReasonCode,
+        _properties: mqtt.Properties | None,
+    ) -> None:
+        if reason_code.is_failure:
+            connect_error.append(f"Broker refused connection: {reason_code}")
+        connected_event.set()
+
+    def _on_publish(
+        _client: mqtt.Client,
+        _userdata: object,
+        _mid: int,
+        _reason_code: mqtt.ReasonCode,
+        _properties: mqtt.Properties | None,
+    ) -> None:
+        published_event.set()
+
+    client.on_connect = _on_connect
+    client.on_publish = _on_publish
+
+    if settings.mqtt_tls_enabled:
+        try:
+            client.tls_set()
+        except Exception as exc:
+            raise _MqttConnectionError(f"TLS setup failed: {exc}") from exc
+
+    if settings.mqtt_username:
+        client.username_pw_set(
+            username=settings.mqtt_username,
+            password=settings.mqtt_password or None,
+        )
+
+    client.loop_start()
+    try:
+        try:
+            client.connect(
+                host=settings.mqtt_broker_host,
+                port=settings.mqtt_broker_port,
+                keepalive=10,
+            )
+        except (OSError, socket.error) as exc:
+            # Sanitise: ensure password never leaks into the error message.
+            msg = _sanitize_mqtt_error(str(exc), settings.mqtt_password)
+            raise _MqttConnectionError(f"Cannot reach broker: {msg}") from exc
+
+        # Wait up to 5 s for connection acknowledgement.
+        if not connected_event.wait(timeout=5):
+            raise _MqttConnectionError("Broker connection timed out (5 s).")
+
+        if connect_error:
+            raise _MqttConnectionError(connect_error[0])
+
+        # Publish test message.
+        client.publish(test_topic, payload=test_payload, qos=1, retain=False)
+        # Wait up to 5 s for the publish ACK (QoS 1).
+        if not published_event.wait(timeout=5):
+            raise _MqttConnectionError("Publish timed out (5 s) — broker reachable but no ACK.")
+
+    finally:
+        try:
+            client.disconnect()
+        except Exception:
+            pass
+        client.loop_stop()
+
+
+def _sanitize_mqtt_error(message: str, password: str | None) -> str:
+    """Replace *password* in *message* with ``[redacted]``."""
+    if password:
+        return message.replace(password, "[redacted]")
+    return message
@@ -0,0 +1,584 @@
+"""Energy data API: prices, costs, summary, DSMR, recompute, Tibber test (M6-T09).
+
+All endpoints are under /api/energy, require an authenticated session, and
+write endpoints (POST) additionally require a non-empty X-CSRF-Token header.
+
+Route prefix note
+-----------------
+This router shares the ``/api/energy`` prefix with ``energy_contracts.py``
+(which handles contract CRUD at /contracts/* and /profiles).  The sub-paths
+used here (/prices, /costs, /costs/summary, /costs/recompute, /dsmr/latest,
+/tibber/test) are disjoint from the contract router's paths, so there is no
+conflict.
+
+Tibber token security
+---------------------
+``POST /api/energy/tibber/test`` calls the Tibber API but **never** echoes the
+token in the response body or in log messages.  Three-state logic mirrors the
+MQTT test endpoint (M5-T10, app/api/routes/api/config.py::post_mqtt_test):
+
+  200 { result: "success",      message: ..., price: {...} }
+  400 { result: "config-error", message: ...               }
+  502 { result: "failed",       message: ...               }
+
+Recompute safety
+----------------
+``POST /api/energy/costs/recompute`` is idempotent: it calls
+``energy_cost.recompute_range`` which upserts existing rows without deleting
+anything.  The endpoint enforces a maximum time-window of 366 days to avoid
+unbounded recomputation triggered by erroneous client requests.
+
+Prices endpoint behaviour
+-------------------------
+``GET /api/energy/prices`` queries the ``tibber_price`` table for tibber
+contracts, or derives the effective fixed-tariff prices for manual contracts
+using the same formula as the billing engine (_manual_strategy in strategies.py):
+
+    buy_dal    = energy.buy.dal    + energy.energy_tax + energy.ode
+    buy_normal = energy.buy.normal + energy.energy_tax + energy.ode
+    sell_dal   = energy.sell.dal    (no tax added to sell price)
+    sell_normal = energy.sell.normal
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime, timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, Query, status
+from fastapi.responses import JSONResponse
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.api.routes.api.deps import require_csrf, require_session
+from app.dependencies import get_app_settings, get_db
+from app.config import Settings
+from app.integrations.tibber.client import (
+    TibberAuthError,
+    TibberError,
+    fetch_current_price,
+)
+from app.models.energy import DsmrReading, EnergyCostPeriod, TibberPrice
+from app.schemas.energy import (
+    CostPeriodSchema,
+    CostsResponse,
+    DsmrLatestResponse,
+    ManualTariffSchema,
+    PricePointSchema,
+    PricesResponse,
+    RecomputeResponse,
+    SummaryResponse,
+    TibberTestPriceSchema,
+    TibberTestResponse,
+)
+from app.services.auth import AuthenticatedSession
+from app.services.contracts import active_contract_version_at
+from app.services.energy_cost import recompute_range, summarize
+from app.services.timezone import local_midnight_utc, local_now
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/energy", tags=["api-energy"])
+
+# Maximum number of cost periods returned per request (mirrors modbus readings cap).
+_COSTS_LIMIT_MAX = 5000
+
+# Maximum allowed time-window for recompute to prevent unbounded computation.
+_RECOMPUTE_MAX_DAYS = 366
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _as_utc(dt: datetime) -> datetime:
+    """Attach UTC tzinfo to a naive datetime (SQLite read-back workaround)."""
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=UTC)
+    return dt
+
+
+def _manual_tariff_from_values(values: dict[str, Any]) -> ManualTariffSchema:
+    """Derive the effective fixed tariff from a manual contract version's values dict.
+
+    Mirrors the _manual_strategy formula (strategies.py):
+        buy_dal    = energy.buy.dal    + energy.energy_tax + energy.ode
+        buy_normal = energy.buy.normal + energy.energy_tax + energy.ode
+        sell_dal   = energy.sell.dal    (no tax added)
+        sell_normal = energy.sell.normal
+    """
+    from decimal import Decimal
+
+    def _d(v: Any) -> Decimal:
+        return Decimal(str(v or 0))
+
+    energy = values.get("energy", {})
+    buy = energy.get("buy", {})
+    sell = energy.get("sell", {})
+    energy_tax = _d(energy.get("energy_tax", 0))
+    ode = _d(energy.get("ode", 0))
+
+    buy_dal = _d(buy.get("dal", 0)) + energy_tax + ode
+    buy_normal = _d(buy.get("normal", 0)) + energy_tax + ode
+    sell_dal = _d(sell.get("dal", 0))
+    sell_normal = _d(sell.get("normal", 0))
+
+    return ManualTariffSchema(
+        buy_dal=float(buy_dal),
+        buy_normal=float(buy_normal),
+        sell_dal=float(sell_dal),
+        sell_normal=float(sell_normal),
+    )
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/prices
+# ---------------------------------------------------------------------------
+
+
+@router.get("/prices", response_model=PricesResponse)
+def get_prices(
+    start: datetime | None = Query(
+        default=None,
+        description="Inclusive start of the time window (ISO 8601). "
+        "Defaults to the start of today UTC when omitted.",
+    ),
+    end: datetime | None = Query(
+        default=None,
+        description="Inclusive end of the time window (ISO 8601). "
+        "Defaults to the end of tomorrow UTC when omitted.",
+    ),
+    limit: int = Query(
+        default=500,
+        ge=1,
+        le=_COSTS_LIMIT_MAX,
+        description="Maximum number of Tibber price points to return.",
+    ),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> PricesResponse:
+    """Return the price curve for the active contract.
+
+    **Tibber contracts** (kind="tibber"):
+        Fetches ``tibber_price`` rows within ``[start, end]``, ordered ascending
+        by ``starts_at``.  At most ``limit`` rows are returned (most recent first
+        within the window, then reversed to ascending order — identical to the
+        modbus readings pattern).
+
+        Response ``points`` carries per-slot:
+        - ``buy  = total``              (Tibber all-inclusive price)
+        - ``sell = total − energy_tax − sell_adjust``  (from active version values)
+        - ``level``                     (Tibber price level, may be null)
+
+        ``tariff`` is null.
+
+    **Manual contracts** (kind="manual"):
+        ``points`` is empty.  ``tariff`` carries the four effective prices
+        derived using the billing engine formula:
+        - ``buy_dal    = energy.buy.dal    + energy_tax + ode``
+        - ``buy_normal = energy.buy.normal + energy_tax + ode``
+        - ``sell_dal   = energy.sell.dal``
+        - ``sell_normal = energy.sell.normal``
+
+    **No active contract**: returns kind=null, currency="EUR", points=[], tariff=null (200).
+    """
+    now = datetime.now(UTC)
+
+    # Default window: today + tomorrow.
+    if start is None:
+        start = now.replace(hour=0, minute=0, second=0, microsecond=0)
+    if end is None:
+        end = (start + timedelta(days=2)).replace(hour=0, minute=0, second=0, microsecond=0)
+
+    start_utc = _as_utc(start)
+    end_utc = _as_utc(end)
+
+    # Resolve the active contract version at the start of the window.
+    version = active_contract_version_at(db, start_utc)
+
+    if version is None:
+        return PricesResponse(
+            kind=None,
+            currency="EUR",
+            points=[],
+            tariff=None,
+        )
+
+    contract = version.contract
+    currency = contract.currency
+
+    if contract.kind == "tibber":
+        # Fetch tibber_price rows in the window.
+        stmt = (
+            select(TibberPrice)
+            .where(
+                TibberPrice.starts_at >= start_utc,
+                TibberPrice.starts_at <= end_utc,
+            )
+            .order_by(TibberPrice.starts_at.desc())
+            .limit(limit)
+        )
+        rows = list(reversed(db.execute(stmt).scalars().all()))
+
+        # Derive sell price per-point using version values (energy_tax + sell_adjust).
+        from decimal import Decimal
+
+        def _d(v: Any) -> Decimal:
+            return Decimal(str(v or 0))
+
+        energy = version.values.get("energy", {}) if version.values else {}
+        energy_tax = _d(energy.get("energy_tax", 0))
+        sell_adjust = _d(energy.get("sell_adjust", 0))
+
+        points = []
+        for row in rows:
+            total = _d(row.total)
+            sell = float(total - energy_tax - sell_adjust)
+            points.append(
+                PricePointSchema(
+                    starts_at=_as_utc(row.starts_at),
+                    buy=row.total,
+                    sell=sell,
+                    level=row.level,
+                )
+            )
+
+        return PricesResponse(
+            kind="tibber",
+            currency=currency,
+            points=points,
+            tariff=None,
+        )
+
+    elif contract.kind == "manual":
+        tariff = _manual_tariff_from_values(version.values or {})
+        return PricesResponse(
+            kind="manual",
+            currency=currency,
+            points=[],
+            tariff=tariff,
+        )
+
+    else:
+        # Unknown kind — return empty response gracefully.
+        return PricesResponse(
+            kind=contract.kind,
+            currency=currency,
+            points=[],
+            tariff=None,
+        )
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/costs
+# ---------------------------------------------------------------------------
+
+
+@router.get("/costs", response_model=CostsResponse)
+def get_costs(
+    start: datetime | None = Query(
+        default=None,
+        description="Inclusive lower bound for period_start (ISO 8601).",
+    ),
+    end: datetime | None = Query(
+        default=None,
+        description="Inclusive upper bound for period_start (ISO 8601).",
+    ),
+    limit: int = Query(
+        default=500,
+        ge=1,
+        le=_COSTS_LIMIT_MAX,
+        description=f"Maximum number of cost periods to return (default 500, max {_COSTS_LIMIT_MAX}).",
+    ),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> CostsResponse:
+    """Return energy_cost_period rows within a time window.
+
+    Rows are ordered by ``period_start`` ascending.  When the window contains
+    more rows than ``limit``, the **most recent** N rows are returned (DESC LIMIT),
+    then reversed to ascending order — identical to the modbus readings pattern.
+
+    Query parameters:
+    - ``start``: inclusive lower bound on ``period_start`` (ISO 8601 datetime).
+    - ``end``:   inclusive upper bound on ``period_start`` (ISO 8601 datetime).
+    - ``limit``: max rows to return (default 500, max {_COSTS_LIMIT_MAX}).
+    """
+    stmt = (
+        select(EnergyCostPeriod)
+        .order_by(EnergyCostPeriod.period_start.desc())
+        .limit(limit)
+    )
+
+    if start is not None:
+        stmt = stmt.where(EnergyCostPeriod.period_start >= _as_utc(start))
+    if end is not None:
+        stmt = stmt.where(EnergyCostPeriod.period_start <= _as_utc(end))
+
+    rows = list(reversed(db.execute(stmt).scalars().all()))
+    items = [CostPeriodSchema.model_validate(r) for r in rows]
+    return CostsResponse(items=items, total=len(items))
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/costs/summary
+# ---------------------------------------------------------------------------
+
+
+@router.get("/costs/summary", response_model=SummaryResponse)
+def get_costs_summary(
+    start: datetime | None = Query(
+        default=None,
+        description=(
+            "Inclusive start of the summary interval (ISO 8601). "
+            "Defaults to the start of the current UTC day."
+        ),
+    ),
+    end: datetime | None = Query(
+        default=None,
+        description=(
+            "Exclusive end of the summary interval (ISO 8601). "
+            "Defaults to the start of the next UTC day (i.e. today's full data)."
+        ),
+    ),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> SummaryResponse:
+    """Aggregate billing for a time interval.
+
+    Calls ``energy_cost.summarize(session, start, end)`` which computes:
+
+        total_payable = Σ(net_cost) + fixed_costs − credits
+
+    where ``fixed_costs`` is (network_fee + management_fee) apportioned to the
+    interval length in days (÷30 per month), and ``credits`` is heffingskorting
+    apportioned similarly (÷365 per year).
+
+    Both ``fixed_costs`` and ``credits`` are derived from the **currently active
+    contract version at ``end``**.  When no active contract exists they are 0.
+    """
+    if start is None or end is None:
+        # Default to the server's local today: [local_midnight, next_local_midnight).
+        # This ensures "today" aligns with the local calendar day (NL time) rather
+        # than UTC midnight.
+        local_today = local_now().date()
+        if start is None:
+            start = local_midnight_utc(local_today)
+        if end is None:
+            end = local_midnight_utc(local_today + timedelta(days=1))
+
+    result = summarize(db, _as_utc(start), _as_utc(end))
+    return SummaryResponse(**result)
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/dsmr/latest
+# ---------------------------------------------------------------------------
+
+
+@router.get("/dsmr/latest", response_model=DsmrLatestResponse)
+def get_dsmr_latest(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> DsmrLatestResponse:
+    """Return the most recent dsmr_reading row.
+
+    Returns ``{"found": false, "recorded_at": null, "payload": null}`` (200, not
+    404) when no rows exist yet, so the front-end can distinguish "no data" from
+    a server error.
+    """
+    row = db.execute(
+        select(DsmrReading)
+        .order_by(DsmrReading.recorded_at.desc())
+        .limit(1)
+    ).scalar_one_or_none()
+
+    if row is None:
+        return DsmrLatestResponse(found=False)
+
+    return DsmrLatestResponse(
+        found=True,
+        recorded_at=_as_utc(row.recorded_at),
+        payload=row.payload,
+    )
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/costs/recompute
+# ---------------------------------------------------------------------------
+
+
+@router.post(
+    "/costs/recompute",
+    responses={
+        200: {"model": RecomputeResponse},
+        422: {"description": "Validation error (missing window or range too large)"},
+    },
+)
+def post_recompute(
+    start: datetime = Query(
+        ...,
+        description="Inclusive start of the recompute window (ISO 8601). Required.",
+    ),
+    end: datetime = Query(
+        ...,
+        description="Exclusive end of the recompute window (ISO 8601). Required.",
+    ),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> RecomputeResponse:
+    """Idempotently recompute billing records in a time window.
+
+    Calls ``energy_cost.recompute_range(session, start, end)`` which overwrites
+    existing rows (including successful ones) for every UTC quarter-hour boundary
+    in ``[start, end)``.
+
+    **Idempotency**: repeated calls with the same window produce the same
+    outcome.  No rows are deleted; only upserted.
+
+    **Window constraint**: the maximum allowed range is {_RECOMPUTE_MAX_DAYS} days.
+    Requests exceeding this return 422.
+
+    Returns the number of periods for which a billing record was written.
+    Periods skipped due to missing contract or missing Tibber price are not counted.
+    """
+    start_utc = _as_utc(start)
+    end_utc = _as_utc(end)
+
+    if end_utc <= start_utc:
+        from fastapi import HTTPException
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="'end' must be strictly after 'start'.",
+        )
+
+    span_days = (end_utc - start_utc).total_seconds() / 86400
+    if span_days > _RECOMPUTE_MAX_DAYS:
+        from fastapi import HTTPException
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=(
+                f"Time window is {span_days:.1f} days which exceeds the maximum of "
+                f"{_RECOMPUTE_MAX_DAYS} days.  Use a smaller window."
+            ),
+        )
+
+    n = recompute_range(db, start_utc, end_utc)
+    logger.info(
+        "POST /api/energy/costs/recompute [%s, %s): wrote %d period(s).",
+        start_utc.isoformat(),
+        end_utc.isoformat(),
+        n,
+    )
+    return RecomputeResponse(recomputed=n)
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/tibber/test
+# ---------------------------------------------------------------------------
+
+
+@router.post(
+    "/tibber/test",
+    responses={
+        200: {"model": TibberTestResponse},
+        400: {"model": TibberTestResponse},
+        502: {"model": TibberTestResponse},
+    },
+)
+def post_tibber_test(
+    settings: Settings = Depends(get_app_settings),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> JSONResponse:
+    """Test Tibber API connectivity by fetching the current price point.
+
+    Three possible outcomes:
+
+    - **200** ``{ result: "success",      message: ..., price: {...} }``
+      The Tibber API responded with a valid current price.  ``price`` contains
+      starts_at, total, energy, tax, currency, and level.
+
+    - **400** ``{ result: "config-error", message: ... }``
+      The Tibber API token is empty or not configured.
+
+    - **502** ``{ result: "failed",       message: ... }``
+      The API call failed (authentication rejected, network error, timeout,
+      unexpected response, etc.).
+
+    The API token is **never** included in the response body or logged.
+    """
+    token = settings.tibber_api_token
+    home_id = settings.tibber_home_id or None  # treat empty string as None
+
+    if not token:
+        logger.info("POST /api/energy/tibber/test: no token configured.")
+        return JSONResponse(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            content=TibberTestResponse(
+                result="config-error",
+                message=(
+                    "Tibber API token is not configured.  "
+                    "Set TIBBER_API_TOKEN in the Config page."
+                ),
+                price=None,
+            ).model_dump(mode="json"),
+        )
+
+    try:
+        price_point = fetch_current_price(token, home_id)
+    except TibberAuthError:
+        logger.warning("POST /api/energy/tibber/test: authentication failed.")
+        return JSONResponse(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            content=TibberTestResponse(
+                result="failed",
+                message=(
+                    "Tibber API authentication failed.  "
+                    "Check that your API token is correct."
+                ),
+                price=None,
+            ).model_dump(mode="json"),
+        )
+    except TibberError as exc:
+        logger.warning("POST /api/energy/tibber/test: API call failed — %s", exc)
+        return JSONResponse(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            content=TibberTestResponse(
+                result="failed",
+                message=f"Tibber API call failed: {exc}",
+                price=None,
+            ).model_dump(mode="json"),
+        )
+
+    price_schema = TibberTestPriceSchema(
+        starts_at=price_point.starts_at,
+        total=price_point.total,
+        energy=price_point.energy,
+        tax=price_point.tax,
+        currency=price_point.currency,
+        level=price_point.level,
+    )
+
+    logger.info(
+        "POST /api/energy/tibber/test: success (starts_at=%s, total=%s %s).",
+        price_point.starts_at.isoformat(),
+        price_point.total,
+        price_point.currency,
+    )
+
+    return JSONResponse(
+        status_code=status.HTTP_200_OK,
+        content=TibberTestResponse(
+            result="success",
+            message=(
+                f"Tibber API connected.  Current price: "
+                f"{price_point.total} {price_point.currency}/kWh "
+                f"(starts {price_point.starts_at.isoformat()})."
+            ),
+            price=price_schema,
+        ).model_dump(mode="json"),
+    )
@@ -0,0 +1,331 @@
+"""EnergyContract CRUD, versioning, and pricing-profile API (M6-T04).
+
+All endpoints are under /api/energy, require an authenticated session, and
+write endpoints (POST/PATCH) additionally require a non-empty X-CSRF-Token
+header.
+
+There is deliberately no DELETE endpoint for contracts: the FK RESTRICT
+constraint on energy_contract_version.contract_id and
+energy_cost_period.contract_version_id prevents accidental deletion of
+contracts that have billing history.  Users should instead deactivate a
+contract (PATCH active=false) to stop it from being used.
+
+Route ordering note
+-------------------
+GET /api/energy/profiles and GET /api/energy/contracts/{id} are on separate
+path prefixes (/energy/profiles vs /energy/contracts/{id}) so there is no
+ambiguity even without extra ordering gymnastics.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.api.routes.api.deps import require_csrf, require_session
+from app.dependencies import get_db
+from app.integrations.pricing.profiles import (
+    ProfileNotFoundError,
+    ProfileValidationError,
+    list_profiles,
+)
+from app.schemas.energy_contract import (
+    ContractCreate,
+    ContractDetailResponse,
+    ContractListResponse,
+    ContractPatch,
+    ContractResponse,
+    ContractVersionResponse,
+    ProfilesResponse,
+    VersionCreate,
+)
+from app.services.auth import AuthenticatedSession
+from app.services import timezone as _tz_mod
+from app.services.contracts import (
+    ContractVersionError,
+    activate_contract,
+    add_version,
+    create_contract,
+    deactivate_contract,
+    get_contract_or_none,
+    list_contracts,
+)
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/energy", tags=["api-energy-contracts"])
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _get_contract_or_404(db: Session, contract_id: int):
+    """Return the contract with the given id or raise 404."""
+    contract = get_contract_or_none(db, contract_id)
+    if contract is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Energy contract {contract_id!r} not found.",
+        )
+    return contract
+
+
+def _contract_detail(db: Session, contract) -> ContractDetailResponse:
+    """Build a ContractDetailResponse for *contract*, loading versions."""
+    # Eager-load versions ordered by effective_from for consistent display.
+    from sqlalchemy import select
+
+    from app.models.energy import EnergyContractVersion
+
+    versions = list(
+        db.execute(
+            select(EnergyContractVersion)
+            .where(EnergyContractVersion.contract_id == contract.id)
+            .order_by(EnergyContractVersion.effective_from)
+        )
+        .scalars()
+        .all()
+    )
+
+    version_schemas = [ContractVersionResponse.model_validate(v) for v in versions]
+    return ContractDetailResponse(
+        id=contract.id,
+        name=contract.name,
+        kind=contract.kind,
+        active=contract.active,
+        currency=contract.currency,
+        created_at=contract.created_at,
+        updated_at=contract.updated_at,
+        versions=version_schemas,
+    )
+
+
+def _raise_422_for_profile_error(exc: Exception) -> Any:
+    """Convert a ProfileValidationError or ProfileNotFoundError into HTTP 422."""
+    raise HTTPException(
+        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+        detail=str(exc),
+    )
+
+
+def _localize_effective_from(dt: datetime | None) -> datetime:
+    """Resolve *dt* to an aware UTC datetime for storage.
+
+    Rules (Principle A):
+    - If *dt* is None → use ``datetime.now(UTC)`` (unchanged from before).
+    - If *dt* is timezone-aware → convert to UTC as-is.
+    - If *dt* is timezone-naive → interpret as server local wall-clock time,
+      localize with ``local_tz()``, then convert to UTC.
+
+    This means a front-end that sends ``"2026-06-25T00:00:00"`` (no Z) has it
+    interpreted as local midnight (e.g. CEST = UTC+2 → stored as 2026-06-24T22:00:00Z),
+    not as UTC midnight.
+    """
+    if dt is None:
+        return datetime.now(UTC)
+    if dt.tzinfo is not None:
+        # Already aware: convert to UTC.
+        return dt.astimezone(UTC)
+    # Naive: assume server local wall-clock.
+    tz = _tz_mod.local_tz()
+    local_dt = dt.replace(tzinfo=tz)
+    return local_dt.astimezone(UTC)
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/profiles
+# ---------------------------------------------------------------------------
+
+
+@router.get("/profiles", response_model=ProfilesResponse)
+def get_profiles(
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ProfilesResponse:
+    """List all available pricing profile structures.
+
+    Returns the full profile structure for each supported contract kind
+    (``manual`` and ``tibber``).  The front-end uses this to dynamically
+    render the correct fields and labels for the contract creation/editing form.
+    """
+    return ProfilesResponse(profiles=list_profiles())
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/contracts
+# ---------------------------------------------------------------------------
+
+
+@router.get("/contracts", response_model=ContractListResponse)
+def list_energy_contracts(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ContractListResponse:
+    """List all energy contracts with their active status.
+
+    Returns a flat list (no embedded version history); use
+    GET /api/energy/contracts/{id} to fetch the full version history for a
+    specific contract.
+    """
+    contracts = list_contracts(db)
+    items = [ContractResponse.model_validate(c) for c in contracts]
+    return ContractListResponse(items=items, total=len(items))
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/contracts
+# ---------------------------------------------------------------------------
+
+
+@router.post(
+    "/contracts",
+    response_model=ContractDetailResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+def create_energy_contract(
+    body: ContractCreate,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ContractDetailResponse:
+    """Create a new energy contract with an initial pricing version.
+
+    The ``values`` dict is validated against the YAML profile for the given
+    ``kind``; non-conforming values result in 422 Unprocessable Entity.
+    The new contract is created with ``active=False``; use
+    PATCH /api/energy/contracts/{id} with ``active=true`` to activate it.
+    """
+    effective_from = _localize_effective_from(body.effective_from)
+
+    try:
+        contract = create_contract(
+            db,
+            name=body.name,
+            kind=body.kind,
+            currency=body.currency,
+            values=body.values,
+            effective_from=effective_from,
+        )
+    except (ProfileNotFoundError, ProfileValidationError) as exc:
+        _raise_422_for_profile_error(exc)
+
+    db.commit()
+    db.refresh(contract)
+    logger.info("Created energy contract id=%d name=%r kind=%s", contract.id, contract.name, contract.kind)
+    return _contract_detail(db, contract)
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/contracts/{id}
+# ---------------------------------------------------------------------------
+
+
+@router.get("/contracts/{contract_id}", response_model=ContractDetailResponse)
+def get_energy_contract(
+    contract_id: int,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ContractDetailResponse:
+    """Return a single energy contract with its full version history.
+
+    Versions are ordered by ``effective_from`` ascending so the caller can
+    easily inspect the pricing timeline.
+    """
+    contract = _get_contract_or_404(db, contract_id)
+    return _contract_detail(db, contract)
+
+
+# ---------------------------------------------------------------------------
+# PATCH /api/energy/contracts/{id}
+# ---------------------------------------------------------------------------
+
+
+@router.patch("/contracts/{contract_id}", response_model=ContractDetailResponse)
+def patch_energy_contract(
+    contract_id: int,
+    body: ContractPatch,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ContractDetailResponse:
+    """Partially update a contract: rename or change activation status.
+
+    - ``name``: updates the human-readable label.
+    - ``active=true``: activates this contract (all others are deactivated).
+    - ``active=false``: deactivates this contract (no effect on others).
+
+    At most one contract may be active at any time; the service layer enforces
+    mutual exclusion.
+    """
+    contract = _get_contract_or_404(db, contract_id)
+
+    if body.name is not None:
+        contract.name = body.name
+        contract.updated_at = datetime.now(UTC)
+
+    if body.active is True:
+        activate_contract(db, contract)
+    elif body.active is False:
+        deactivate_contract(db, contract)
+
+    db.commit()
+    db.refresh(contract)
+    return _contract_detail(db, contract)
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/contracts/{id}/versions
+# ---------------------------------------------------------------------------
+
+
+@router.post(
+    "/contracts/{contract_id}/versions",
+    response_model=ContractDetailResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+def add_contract_version(
+    contract_id: int,
+    body: VersionCreate,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ContractDetailResponse:
+    """Add a new pricing version to an existing contract.
+
+    This is how price changes are recorded: the current open version is
+    automatically closed (its ``effective_to`` is set to ``body.effective_from``)
+    and a new version is created starting at ``body.effective_from``.
+
+    The ``values`` dict must conform to the contract's pricing profile.
+    Non-conforming values return 422.  If ``effective_from`` is not strictly
+    after the previous version's ``effective_from``, 422 is returned without
+    writing any rows.
+
+    Historical versions are never modified; this endpoint is append-only.
+    """
+    contract = _get_contract_or_404(db, contract_id)
+    effective_from = _localize_effective_from(body.effective_from)
+
+    try:
+        add_version(
+            db,
+            contract,
+            effective_from=effective_from,
+            values=body.values,
+        )
+    except ContractVersionError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=str(exc),
+        )
+    except (ProfileNotFoundError, ProfileValidationError) as exc:
+        _raise_422_for_profile_error(exc)
+
+    db.commit()
+    db.refresh(contract)
+    return _contract_detail(db, contract)
@@ -0,0 +1,221 @@
+"""Expose API routes (M5-T12).
+
+Three endpoints:
+  GET  /api/expose           — Return catalog of exposable entities, per-key
+                               toggle state, and MQTT/Discovery connection status.
+  PUT  /api/expose           — Set per-key toggle state (map key → bool);
+                               triggers a HA Discovery re-publish on success.
+  POST /api/expose/republish — Manually trigger a full HA Discovery re-publish.
+
+Auth model:
+  - GET: session required (no CSRF — read-only).
+  - PUT, POST: session + CSRF required.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.api.routes.api.deps import require_csrf, require_session
+from app.config import get_settings
+from app.dependencies import get_db
+from app.services.config_page import build_runtime_settings
+from app.integrations.expose import CatalogEntry, build_catalog
+from app.integrations.mqtt import mqtt_manager
+from app.models.expose import ExposedEntityToggle
+from app.schemas.expose import (
+    CatalogEntrySchema,
+    DeviceInfoSchema,
+    ExposeResponse,
+    ExposeUpdateRequest,
+    ExposeUpdateResponse,
+    ExposableEntitySchema,
+    MqttStatusSchema,
+    RepublishResponse,
+)
+from app.services.auth import AuthenticatedSession
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api", tags=["api-expose"])
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _get_mqtt_status(db: Session) -> MqttStatusSchema:
+    """Build MQTT/Discovery status from live runtime state (DB-merged settings)."""
+    settings = build_runtime_settings(db, get_settings())
+    return MqttStatusSchema(
+        mqtt_configured=mqtt_manager.is_configured(settings),
+        mqtt_connected=mqtt_manager.is_connected,
+        discovery_enabled=bool(settings.ha_discovery_enabled),
+    )
+
+
+def _entry_to_schema(entry: CatalogEntry) -> CatalogEntrySchema:
+    """Convert a CatalogEntry to its Pydantic schema form.
+
+    Excludes ``value_getter`` because it is a non-serialisable callable.
+    """
+    entity = entry.entity
+    return CatalogEntrySchema(
+        entity=ExposableEntitySchema(
+            key=entity.key,
+            component=entity.component,
+            device=DeviceInfoSchema(
+                identifiers=list(entity.device.identifiers),
+                name=entity.device.name,
+            ),
+            device_class=entity.device_class,
+            unit=entity.unit,
+            name=entity.name,
+            state_class=entity.state_class,
+        ),
+        enabled=entry.enabled,
+    )
+
+
+def _build_response_data(
+    session: Session,
+) -> tuple[list[CatalogEntrySchema], MqttStatusSchema]:
+    """Return (catalog_entries, mqtt_status) for building GET / PUT responses."""
+    catalog = build_catalog(session)
+    catalog_schema = [_entry_to_schema(e) for e in catalog]
+    mqtt_status = _get_mqtt_status(session)
+    return catalog_schema, mqtt_status
+
+
+# ---------------------------------------------------------------------------
+# GET /api/expose
+# ---------------------------------------------------------------------------
+
+
+@router.get("/expose", response_model=ExposeResponse)
+def get_expose(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ExposeResponse:
+    """Return the full exposable-entity catalog with toggle states and MQTT status.
+
+    The catalog is computed dynamically from registered providers (e.g. the
+    Modbus provider enumerates all enabled devices and their metric entities).
+    Toggle states come from the ``exposed_entity_toggle`` table; entities with
+    no row default to ``enabled=False``.
+    """
+    catalog_schema, mqtt_status = _build_response_data(db)
+    return ExposeResponse(catalog=catalog_schema, mqtt_status=mqtt_status)
+
+
+# ---------------------------------------------------------------------------
+# PUT /api/expose
+# ---------------------------------------------------------------------------
+
+
+@router.put("/expose", response_model=ExposeUpdateResponse)
+def put_expose(
+    body: ExposeUpdateRequest,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ExposeUpdateResponse:
+    """Set per-entity toggle state.
+
+    Accepts a map of ``{key: bool}`` and upserts rows in the
+    ``exposed_entity_toggle`` table.  Only keys present in ``body.toggles``
+    are touched; other entities' toggles are left unchanged.
+
+    After writing the toggles, triggers a HA Discovery re-publish so any
+    changes (enabled ↔ disabled) are reflected in Home Assistant immediately.
+    """
+    now = datetime.now(UTC)
+
+    for key, enabled in body.toggles.items():
+        existing = (
+            db.query(ExposedEntityToggle)
+            .filter(ExposedEntityToggle.key == key)
+            .first()
+        )
+        if existing is not None:
+            existing.enabled = enabled
+            existing.updated_at = now
+        else:
+            db.add(
+                ExposedEntityToggle(
+                    key=key,
+                    enabled=enabled,
+                    updated_at=now,
+                )
+            )
+
+    db.commit()
+
+    # Trigger discovery re-publish after toggle change.
+    _trigger_republish(db)
+
+    catalog_schema, mqtt_status = _build_response_data(db)
+    return ExposeUpdateResponse(catalog=catalog_schema, mqtt_status=mqtt_status)
+
+
+# ---------------------------------------------------------------------------
+# POST /api/expose/republish
+# ---------------------------------------------------------------------------
+
+
+@router.post("/expose/republish", response_model=RepublishResponse)
+def post_expose_republish(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> RepublishResponse:
+    """Manually trigger a full HA Discovery re-publish.
+
+    Calls ``publish_discovery(session)`` from the HA discovery service (M5-T11).
+    Returns a status indicating whether the publish was attempted (or skipped
+    because MQTT / discovery is not enabled / connected).
+    """
+    settings = build_runtime_settings(db, get_settings())
+    if not (settings.mqtt_enabled and settings.ha_discovery_enabled and mqtt_manager.is_connected):
+        return RepublishResponse(
+            ok=False,
+            message="MQTT / HA Discovery not enabled or broker not connected.",
+        )
+
+    try:
+        _trigger_republish(db)
+        return RepublishResponse(
+            ok=True,
+            message="HA Discovery re-published successfully.",
+        )
+    except Exception as exc:
+        logger.exception("post_expose_republish: unexpected error during publish")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Discovery re-publish failed.",
+        ) from exc
+
+
+# ---------------------------------------------------------------------------
+# Internal: trigger discovery re-publish
+# ---------------------------------------------------------------------------
+
+
+def _trigger_republish(session: Session) -> None:
+    """Call publish_discovery from the HA discovery service.
+
+    No-op if MQTT / discovery is not enabled or broker is not connected
+    (publish_discovery guards internally).  All errors are swallowed to avoid
+    breaking the API response.
+    """
+    try:
+        from app.services.ha_discovery import publish_discovery
+
+        publish_discovery(session)
+    except Exception:
+        logger.exception("_trigger_republish: publish_discovery raised an error")
@@ -0,0 +1,331 @@
+"""Meter CRUD, swap declaration, and retroactive recompute API (M7-T05).
+
+All endpoints are under /api/energy/meters, require an authenticated session,
+and write endpoints (POST/PATCH) additionally require a non-empty X-CSRF-Token
+header.
+
+Route semantics
+---------------
+GET    /api/energy/meters         — list all meter epochs (ascending started_at)
+POST   /api/energy/meters         — declare a meter swap / initial meter epoch
+PATCH  /api/energy/meters/{id}    — edit label / note, or correct started_at (retroactive)
+
+Retroactive recompute
+---------------------
+Whenever a write operation changes a meter's ``started_at`` (new declaration
+or PATCH correction), the affected billing window is re-judged via
+``recompute_range``:
+
+- **POST** (new meter, possibly retroactive):
+    window = [new_meter.started_at, now)
+    Rationale: the new meter's ``started_at`` closes the previous meter at that
+    point; all periods from that boundary forward may have a different meter
+    attribution.  Using ``now`` as the upper bound is safe because
+    ``recompute_range`` only processes closed quarters and the operation is
+    idempotent.
+
+- **PATCH started_at** (retroactive correction):
+    window = [min(old_started_at, new_started_at), now)
+    Rationale: shifting the boundary in either direction affects all periods
+    between the old and new boundary (and potentially beyond if re-attribution
+    cascades).  Using the minimum of the two timestamps guarantees the entire
+    affected range is covered; using ``now`` as the upper bound is safe and
+    idempotent.
+
+``started_at`` localisation (Principle A, FU10 convention)
+----------------------------------------------------------
+If the client sends a timezone-naive ``started_at`` value, it is interpreted as
+the **server's local wall-clock time** and converted to UTC before storage.
+Timezone-aware values are converted to UTC as-is.  This is identical to the
+``_localize_effective_from`` convention used in ``energy_contracts.py``.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+from typing import Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.api.routes.api.deps import require_csrf, require_session
+from app.dependencies import get_db
+from app.models.energy import Meter
+from app.schemas.meter import (
+    MeterDeclareRequest,
+    MeterListResponse,
+    MeterPatchRequest,
+    MeterResponse,
+)
+from app.services import timezone as _tz_mod
+from app.services.auth import AuthenticatedSession
+from app.services.energy_cost import recompute_range
+from app.services.meters import (
+    MeterIntervalError,
+    MeterOverlapError,
+    declare_meter,
+    list_meters,
+    update_meter,
+)
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/energy", tags=["api-energy-meters"])
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _trigger_discovery_republish(session: Session) -> None:
+    """Call publish_discovery after a meter write operation (best-effort).
+
+    No-op if MQTT / discovery is not enabled or the broker is not connected
+    (publish_discovery guards internally).  All errors are swallowed so that a
+    discovery failure never breaks the API response.
+
+    Must be called **after** db.commit() so that publish_discovery sees the
+    final committed state of the meter table when it rebuilds the catalog.
+    """
+    try:
+        from app.services.ha_discovery import publish_discovery
+
+        publish_discovery(session)
+    except Exception:
+        logger.exception("_trigger_discovery_republish: publish_discovery raised an error")
+
+
+def _get_meter_or_404(db: Session, meter_id: int) -> Meter:
+    """Return the meter with the given id or raise 404."""
+    meter: Optional[Meter] = db.get(Meter, meter_id)
+    if meter is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Meter {meter_id!r} not found.",
+        )
+    return meter
+
+
+def _localize_started_at(dt: datetime) -> datetime:
+    """Resolve *dt* to an aware UTC datetime for storage.
+
+    Follows the same Principle-A convention as ``_localize_effective_from``
+    in ``energy_contracts.py`` (FU10):
+
+    - Timezone-aware → convert to UTC as-is.
+    - Timezone-naive → interpret as server local wall-clock time, localize
+      with ``local_tz()``, then convert to UTC.
+
+    A front-end sending ``"2026-06-25T00:00:00"`` (no Z) has it interpreted
+    as local midnight (e.g. CEST = UTC+2 → stored as 2026-06-24T22:00:00Z),
+    not as UTC midnight.
+    """
+    if dt.tzinfo is not None:
+        return dt.astimezone(UTC)
+    tz = _tz_mod.local_tz()
+    local_dt = dt.replace(tzinfo=tz)
+    return local_dt.astimezone(UTC)
+
+
+def _trigger_recompute(db: Session, start: datetime, label: str) -> int:
+    """Trigger recompute_range from *start* to now (UTC).
+
+    This is the standard "retroactive window" call: everything from the
+    affected boundary up to the current moment needs re-attribution.
+    Using ``now`` as the upper bound is safe because ``recompute_range``
+    only touches closed quarter-hour periods and the operation is idempotent.
+    """
+    end = datetime.now(UTC)
+    if start >= end:
+        # started_at is in the future — nothing to recompute.
+        logger.info("%s: started_at (%s) is in the future, skipping recompute.", label, start)
+        return 0
+    n = recompute_range(db, start, end)
+    logger.info(
+        "%s: recomputed %d period(s) in window [%s, %s).",
+        label,
+        n,
+        start.isoformat(),
+        end.isoformat(),
+    )
+    return n
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/meters
+# ---------------------------------------------------------------------------
+
+
+@router.get("/meters", response_model=MeterListResponse)
+def list_energy_meters(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> MeterListResponse:
+    """List all meter epochs in ascending ``started_at`` order.
+
+    Returns the full historical sequence of meter installations across all
+    commodities.  The active meter (``ended_at=null``) appears last because it
+    has the latest ``started_at``.
+    """
+    meters = list_meters(db)
+    items = [MeterResponse.model_validate(m) for m in meters]
+    return MeterListResponse(items=items, total=len(items))
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/meters
+# ---------------------------------------------------------------------------
+
+
+@router.post(
+    "/meters",
+    response_model=MeterResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+def declare_energy_meter(
+    body: MeterDeclareRequest,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> MeterResponse:
+    """Declare a new meter epoch (swap, home move, or initial declaration).
+
+    Closes the current active meter for the given commodity at ``started_at``
+    and opens a new active meter.  If no active meter exists, the new meter is
+    simply created without closing anything.
+
+    **Validation**: ``started_at`` must be **≥** the current active meter's
+    own ``started_at`` (no chronological backdate below the active epoch's
+    start).  Equal timestamps are allowed (replaces the current meter at the
+    same logical moment).  Violation → 422.
+
+    **Retroactive recompute**: if ``started_at`` is in the past, billing
+    records from that point forward are re-judged via ``recompute_range`` to
+    reflect the new meter attribution.  The recompute is transparent — the
+    response body is the created meter (``MeterResponse``) only and does **not**
+    include a recompute count; callers should re-fetch costs if they need the
+    updated totals.
+    """
+    started_at_utc = _localize_started_at(body.started_at)
+
+    try:
+        new_meter = declare_meter(
+            db,
+            label=body.label,
+            started_at=started_at_utc,
+            reason=body.reason.value,
+            commodity=body.commodity,
+            note=body.note,
+        )
+    except MeterOverlapError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=str(exc),
+        )
+
+    db.flush()  # assign PK before recompute (recompute uses session, needs meter in DB)
+
+    # Retroactive recompute: re-judge attribution from the new boundary onward.
+    now = datetime.now(UTC)
+    if started_at_utc < now:
+        _trigger_recompute(db, started_at_utc, "POST /api/energy/meters")
+
+    db.commit()
+    db.refresh(new_meter)
+
+    # Trigger HA discovery re-publish so the new active meter's energy-cost
+    # device/sensor configuration is pushed to Home Assistant.  Best-effort:
+    # failures are logged and swallowed; the API response is not affected.
+    _trigger_discovery_republish(db)
+
+    logger.info(
+        "POST /api/energy/meters: declared %r meter id=%d label=%r started_at=%s",
+        body.commodity,
+        new_meter.id,
+        new_meter.label,
+        started_at_utc.isoformat(),
+    )
+    return MeterResponse.model_validate(new_meter)
+
+
+# ---------------------------------------------------------------------------
+# PATCH /api/energy/meters/{id}
+# ---------------------------------------------------------------------------
+
+
+@router.patch("/meters/{meter_id}", response_model=MeterResponse)
+def patch_energy_meter(
+    meter_id: int,
+    body: MeterPatchRequest,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> MeterResponse:
+    """Partially update a meter epoch: rename, edit note, or correct started_at.
+
+    - ``label``: updates the human-readable label.
+    - ``note``: updates the free-form note.
+    - ``started_at``: **retroactive correction** — shifts this meter's start
+      boundary.  The service layer maintains timeline continuity by also
+      updating the preceding meter's ``ended_at``.  Validation:
+        * Must be strictly after the previous meter's own ``started_at``.
+        * Must be strictly before this meter's ``ended_at`` (if closed).
+      Violation → 422.
+
+    **Retroactive recompute when ``started_at`` changes**: billing records in
+    the window ``[min(old, new), now)`` are re-judged to reflect the corrected
+    meter attribution.
+
+    Not found → 404.
+    """
+    meter = _get_meter_or_404(db, meter_id)
+
+    # Capture old started_at before mutation (needed for recompute window).
+    old_started_at: Optional[datetime] = meter.started_at
+
+    # Localise started_at if provided.
+    new_started_at_utc: Optional[datetime] = None
+    if body.started_at is not None:
+        new_started_at_utc = _localize_started_at(body.started_at)
+
+    try:
+        update_meter(
+            db,
+            meter,
+            label=body.label,
+            note=body.note,
+            started_at=new_started_at_utc,
+        )
+    except MeterIntervalError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=str(exc),
+        )
+
+    # Retroactive recompute if started_at was changed.
+    if new_started_at_utc is not None and old_started_at is not None:
+        # Normalise old_started_at to UTC-aware for comparison.
+        if old_started_at.tzinfo is None:
+            old_started_at = old_started_at.replace(tzinfo=UTC)
+        # Window = [min(old, new), now) — covers all periods whose attribution
+        # may have changed due to the boundary shift in either direction.
+        window_start = min(old_started_at, new_started_at_utc)
+        _trigger_recompute(db, window_start, f"PATCH /api/energy/meters/{meter_id}")
+
+    db.commit()
+    db.refresh(meter)
+
+    # Trigger HA discovery re-publish so label renames on the active meter
+    # propagate to the HA device name.  Best-effort: failures are logged and
+    # swallowed; the API response is not affected.
+    _trigger_discovery_republish(db)
+
+    logger.info(
+        "PATCH /api/energy/meters/%d: updated meter label=%r started_at=%s",
+        meter_id,
+        meter.label,
+        meter.started_at,
+    )
+    return MeterResponse.model_validate(meter)
@@ -0,0 +1,510 @@
+"""Modbus device CRUD, readings, metrics, and test-read API (M5-T05).
+
+All endpoints are under /api/modbus, require an authenticated session, and
+write endpoints (POST/PATCH/DELETE + test-read) additionally require a
+non-empty X-CSRF-Token header.
+
+Deletion safety:
+    DELETE /api/modbus/devices/{uuid} queries the application layer for
+    existing modbus_reading rows before deleting.  Without ``cascade`` it
+    returns 409 and suggests disabling the device instead — a friendly guard
+    rather than letting the DB raise.  With ``cascade=true`` it removes the
+    readings (and expose toggles) first, then the device.  SQLite FK RESTRICT
+    *is* enforced at runtime here (the app sets PRAGMA foreign_keys=ON; see
+    app/db.py), so the cascade delete order matters.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy import delete as sa_delete, func, select
+from sqlalchemy.orm import Session
+
+from app.api.routes.api.deps import require_csrf, require_session
+from app.dependencies import get_db
+from app.integrations.modbus import driver as modbus_driver
+from app.integrations.modbus.driver import ModbusDriverError
+from app.integrations.modbus.profiles import (
+    ProfileNotFoundError,
+    decode as decode_profile,
+    list_profiles,
+    load_profile,
+)
+from app.models.expose import ExposedEntityToggle
+from app.models.modbus import ModbusDevice, ModbusReading
+from app.schemas.modbus import (
+    MetricInfo,
+    ModbusDeleteResponse,
+    ModbusDeviceCreate,
+    ModbusDeviceListResponse,
+    ModbusDeviceResponse,
+    ModbusDeviceUpdate,
+    ModbusLatestResponse,
+    ModbusMetricsResponse,
+    ModbusProfilesResponse,
+    ModbusReadingResponse,
+    ModbusReadingsResponse,
+    ModbusTestReadResponse,
+    ProfileSummary,
+)
+from app.services.auth import AuthenticatedSession
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/modbus", tags=["api-modbus"])
+
+# Maximum number of readings that can be returned per request.
+_READINGS_LIMIT_MAX = 5000
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _get_device_or_404(db: Session, uuid: str) -> ModbusDevice:
+    """Return the device with the given UUID or raise 404."""
+    device = db.execute(
+        select(ModbusDevice).where(ModbusDevice.uuid == uuid)
+    ).scalar_one_or_none()
+    if device is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Device '{uuid}' not found.",
+        )
+    return device
+
+
+def _label_from_key(key: str) -> str:
+    """Derive a human-readable label from a metric key.
+
+    Example: ``"active_power"`` → ``"Active Power"``
+    """
+    return key.replace("_", " ").title()
+
+
+# ---------------------------------------------------------------------------
+# GET /api/modbus/profiles
+# ---------------------------------------------------------------------------
+
+
+@router.get("/profiles", response_model=ModbusProfilesResponse)
+def get_profiles(
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusProfilesResponse:
+    """List all available Modbus YAML profiles (name + description).
+
+    Intended for the front-end's device-creation profile drop-down.
+    """
+    pairs = list_profiles()
+    return ModbusProfilesResponse(
+        profiles=[ProfileSummary(name=name, description=desc) for name, desc in pairs]
+    )
+
+
+# ---------------------------------------------------------------------------
+# Device CRUD
+# ---------------------------------------------------------------------------
+
+
+@router.get("/devices", response_model=ModbusDeviceListResponse)
+def list_devices(
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusDeviceListResponse:
+    """Return all Modbus devices (no pagination — device counts stay small)."""
+    devices = db.execute(select(ModbusDevice)).scalars().all()
+    items = [ModbusDeviceResponse.model_validate(d) for d in devices]
+    return ModbusDeviceListResponse(items=items, total=len(items))
+
+
+@router.post(
+    "/devices",
+    response_model=ModbusDeviceResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+def create_device(
+    body: ModbusDeviceCreate,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ModbusDeviceResponse:
+    """Create a new Modbus device.
+
+    - Validates that the referenced ``profile`` exists; returns 422 if not.
+    - Returns 201 with the created device on success.
+    """
+    # Validate profile exists (422 if not)
+    try:
+        load_profile(body.profile)
+    except ProfileNotFoundError:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Profile '{body.profile}' does not exist.",
+        )
+
+    now = datetime.now(UTC)
+    device = ModbusDevice(
+        friendly_name=body.friendly_name,
+        transport=body.transport,
+        host=body.host,
+        port=body.port,
+        unit_id=body.unit_id,
+        profile=body.profile,
+        poll_interval_s=body.poll_interval_s,
+        enabled=body.enabled,
+        created_at=now,
+        updated_at=now,
+    )
+    db.add(device)
+    db.commit()
+    db.refresh(device)
+    logger.info("Created Modbus device %r (uuid=%s)", device.friendly_name, device.uuid)
+    return ModbusDeviceResponse.model_validate(device)
+
+
+@router.get("/devices/{uuid}", response_model=ModbusDeviceResponse)
+def get_device(
+    uuid: str,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusDeviceResponse:
+    """Return a single Modbus device by UUID."""
+    device = _get_device_or_404(db, uuid)
+    return ModbusDeviceResponse.model_validate(device)
+
+
+@router.patch("/devices/{uuid}", response_model=ModbusDeviceResponse)
+def patch_device(
+    uuid: str,
+    body: ModbusDeviceUpdate,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ModbusDeviceResponse:
+    """Partially update a Modbus device (including enable/disable).
+
+    Only fields explicitly provided in the request body are updated.
+    Providing ``profile`` triggers a profile-existence check (422 if unknown).
+    """
+    device = _get_device_or_404(db, uuid)
+
+    update_data = body.model_dump(exclude_none=True)
+
+    # If profile is being changed, validate it exists.
+    if "profile" in update_data:
+        try:
+            load_profile(update_data["profile"])
+        except ProfileNotFoundError:
+            raise HTTPException(
+                status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                detail=f"Profile '{update_data['profile']}' does not exist.",
+            )
+
+    for field, value in update_data.items():
+        setattr(device, field, value)
+
+    device.updated_at = datetime.now(UTC)
+    db.commit()
+    db.refresh(device)
+    logger.info("Updated Modbus device %r (uuid=%s)", device.friendly_name, device.uuid)
+    return ModbusDeviceResponse.model_validate(device)
+
+
+@router.delete(
+    "/devices/{uuid}",
+    status_code=status.HTTP_204_NO_CONTENT,
+    response_model=None,
+)
+def delete_device(
+    uuid: str,
+    cascade: bool = Query(default=False),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> None | ModbusDeleteResponse:
+    """Delete a Modbus device.
+
+    **Default behaviour (cascade=false)**:
+    Returns 409 Conflict if the device has any associated readings; use
+    ``enabled=false`` to disable it instead.
+
+    **Cascade delete (cascade=true)**:
+    Permanently deletes the device together with all its readings and any
+    ``ExposedEntityToggle`` rows whose key matches ``modbus.<uuid>.*``.
+    Also makes a best-effort attempt to clear the device's HA Discovery
+    config topics from MQTT (empty retained payload) before the DB rows
+    are removed.  MQTT failures are swallowed — the DB deletion proceeds
+    regardless.
+    Returns HTTP 200 with a ``ModbusDeleteResponse`` JSON body on success.
+
+    **Application-layer safety**: the 409 guard uses an explicit SELECT COUNT
+    query to return a friendly message.  FK RESTRICT is enforced at runtime
+    (the app sets ``PRAGMA foreign_keys=ON``), so the cascade path deletes
+    readings before the device.
+    """
+    from app.services.ha_discovery import clear_device_discovery
+
+    device = _get_device_or_404(db, uuid)
+
+    # Application-layer guard: refuse deletion if any readings exist.
+    reading_count: int = db.execute(
+        select(func.count(ModbusReading.id)).where(ModbusReading.device_id == device.id)
+    ).scalar_one()
+
+    if reading_count > 0 and not cascade:
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail=(
+                f"Device '{uuid}' has {reading_count} associated reading(s) and cannot be "
+                "deleted.  Disable the device (set enabled=false) instead to stop polling "
+                "without losing historical data."
+            ),
+        )
+
+    if cascade:
+        # --- Cascade deletion path ---
+        logger.info(
+            "Cascade-deleting Modbus device %r (uuid=%s): %d reading(s)",
+            device.friendly_name,
+            uuid,
+            reading_count,
+        )
+
+        # 1. Best-effort HA Discovery cleanup (before DB rows are gone).
+        try:
+            clear_device_discovery(db, uuid)
+        except Exception:  # noqa: BLE001
+            logger.exception(
+                "delete_device(cascade): HA discovery cleanup raised for uuid=%s; continuing",
+                uuid,
+            )
+
+        # 2. Delete all readings for this device (must happen before device row).
+        deleted_readings_result = db.execute(
+            sa_delete(ModbusReading).where(ModbusReading.device_id == device.id)
+        )
+        readings_deleted: int = deleted_readings_result.rowcount
+
+        # 3. Delete all ExposedEntityToggle rows for this device.
+        #    Keys follow the pattern "modbus.<uuid>.<metric>".
+        toggle_prefix = f"modbus.{uuid}.%"
+        deleted_toggles_result = db.execute(
+            sa_delete(ExposedEntityToggle).where(ExposedEntityToggle.key.like(toggle_prefix))
+        )
+        toggles_deleted: int = deleted_toggles_result.rowcount
+
+        # 4. Delete the device itself.
+        db.delete(device)
+        db.commit()
+
+        logger.info(
+            "Cascade-delete complete for device uuid=%s: %d reading(s), %d toggle(s) removed",
+            uuid,
+            readings_deleted,
+            toggles_deleted,
+        )
+
+        from fastapi.responses import JSONResponse
+        return JSONResponse(
+            status_code=status.HTTP_200_OK,
+            content={
+                "deleted": True,
+                "readings_deleted": readings_deleted,
+                "toggles_deleted": toggles_deleted,
+            },
+        )
+
+    # --- Non-cascade path (no readings exist at this point) ---
+    logger.info("Deleting Modbus device %r (uuid=%s)", device.friendly_name, uuid)
+    db.delete(device)
+    db.commit()
+
+
+# ---------------------------------------------------------------------------
+# Readings endpoints
+# ---------------------------------------------------------------------------
+
+
+@router.get("/devices/{uuid}/latest", response_model=ModbusLatestResponse)
+def get_latest_reading(
+    uuid: str,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusLatestResponse:
+    """Return the most recent reading for a device.
+
+    If no readings exist yet, returns ``{"found": false, "recorded_at": null,
+    "payload": null}`` (200, not 404) so the front-end can distinguish
+    "device exists but has no data" from "device not found".
+    """
+    device = _get_device_or_404(db, uuid)
+
+    row = db.execute(
+        select(ModbusReading)
+        .where(ModbusReading.device_id == device.id)
+        .order_by(ModbusReading.recorded_at.desc())
+        .limit(1)
+    ).scalar_one_or_none()
+
+    if row is None:
+        return ModbusLatestResponse(found=False, recorded_at=None, payload=None)
+
+    return ModbusLatestResponse(
+        found=True,
+        recorded_at=row.recorded_at,
+        payload=row.payload,
+    )
+
+
+@router.get("/devices/{uuid}/readings", response_model=ModbusReadingsResponse)
+def get_readings(
+    uuid: str,
+    start: datetime | None = Query(default=None),
+    end: datetime | None = Query(default=None),
+    limit: int = Query(default=500, ge=1, le=_READINGS_LIMIT_MAX),
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusReadingsResponse:
+    """Return time-range readings for a device.
+
+    When the window contains more rows than ``limit``, the **most recent** N rows
+    are returned (``ORDER BY recorded_at DESC LIMIT n``), then reversed to
+    ascending order before being sent to the client.  This ensures that for long
+    time-range requests (e.g. 6 h / 24 h) the caller always sees the latest data
+    rather than the oldest segment of the window.
+
+    When the window has fewer rows than ``limit`` the full window is returned in
+    ascending order — behaviour is identical to a plain ascending query.
+
+    The response schema is unchanged: items are always ``recorded_at`` ascending.
+
+    The query uses the ``(device_id, recorded_at)`` composite index for
+    efficient time-window scans.
+
+    Query parameters:
+    - ``start``: inclusive lower bound (ISO8601 datetime)
+    - ``end``: inclusive upper bound (ISO8601 datetime)
+    - ``limit``: max rows to return (default 500, max {_READINGS_LIMIT_MAX})
+    """
+    device = _get_device_or_404(db, uuid)
+
+    stmt = (
+        select(ModbusReading)
+        .where(ModbusReading.device_id == device.id)
+        .order_by(ModbusReading.recorded_at.desc())
+        .limit(limit)
+    )
+
+    if start is not None:
+        stmt = stmt.where(ModbusReading.recorded_at >= start)
+    if end is not None:
+        stmt = stmt.where(ModbusReading.recorded_at <= end)
+
+    # Fetch most-recent N rows, then reverse to restore ascending order for the response.
+    rows = list(reversed(db.execute(stmt).scalars().all()))
+    items = [ModbusReadingResponse(recorded_at=r.recorded_at, payload=r.payload) for r in rows]
+    return ModbusReadingsResponse(items=items)
+
+
+# ---------------------------------------------------------------------------
+# Metrics endpoint
+# ---------------------------------------------------------------------------
+
+
+@router.get("/devices/{uuid}/metrics", response_model=ModbusMetricsResponse)
+def get_metrics(
+    uuid: str,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+) -> ModbusMetricsResponse:
+    """Return the metric catalogue for a device's profile.
+
+    Each entry has ``key``, ``label`` (derived from key if the profile has
+    none — underscores → spaces, title-cased), ``unit``, and ``device_class``.
+    This is the authoritative metadata source for front-end card labels and
+    chart axis labels.
+    """
+    device = _get_device_or_404(db, uuid)
+
+    try:
+        profile = load_profile(device.profile)
+    except ProfileNotFoundError:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Device profile '{device.profile}' could not be loaded.",
+        )
+
+    metrics = [
+        MetricInfo(
+            key=m.key,
+            label=_label_from_key(m.key),
+            unit=m.unit,
+            device_class=m.device_class,
+        )
+        for m in profile.metrics
+    ]
+
+    return ModbusMetricsResponse(profile=profile.name, metrics=metrics)
+
+
+# ---------------------------------------------------------------------------
+# Test-read endpoint
+# ---------------------------------------------------------------------------
+
+
+@router.post("/devices/{uuid}/test", response_model=ModbusTestReadResponse)
+def test_read(
+    uuid: str,
+    db: Session = Depends(get_db),
+    _auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> ModbusTestReadResponse:
+    """Immediately read and decode the device once without persisting any data.
+
+    Useful for validating gateway connectivity and Modbus address settings
+    before relying on the background polling job.
+
+    This is a write-class endpoint (it initiates network I/O on demand) and
+    therefore requires a CSRF token.  The response payload is never stored.
+    """
+    device = _get_device_or_404(db, uuid)
+
+    try:
+        profile = load_profile(device.profile)
+    except ProfileNotFoundError:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Device profile '{device.profile}' could not be loaded.",
+        )
+
+    try:
+        registers = modbus_driver.read_blocks(
+            device.host,
+            device.port,
+            device.unit_id,
+            [{"start": b.start, "count": b.count} for b in profile.blocks],
+        )
+        payload: dict[str, Any] = decode_profile(profile, registers)
+        return ModbusTestReadResponse(ok=True, payload=payload)
+
+    except ModbusDriverError as exc:
+        logger.warning(
+            "Test read failed for device %r (uuid=%s): %s",
+            device.friendly_name,
+            uuid,
+            exc,
+        )
+        return ModbusTestReadResponse(ok=False, error=str(exc))
+    except Exception as exc:  # noqa: BLE001
+        logger.warning(
+            "Unexpected error during test read for device %r (uuid=%s): %s",
+            device.friendly_name,
+            uuid,
+            exc,
+        )
+        return ModbusTestReadResponse(ok=False, error=f"Unexpected error: {exc}")
@@ -2,7 +2,7 @@ from __future__ import annotations

 import logging

-from fastapi import APIRouter, Depends, HTTPException, Response, status
+from fastapi import APIRouter, Depends, HTTPException, Request, Response, status
 from sqlalchemy.orm import Session

 from app.api.routes.api.deps import require_csrf, require_session
@@ -14,6 +14,12 @@ from app.schemas.session import (
    SessionResponse,
    SessionUser,
 )
+from app.schemas.totp import (
+    TotpDisableRequest,
+    TotpEnableRequest,
+    TotpSetupResponse,
+    TotpStatusResponse,
+)
 from app.services.auth import (
    AuthPasswordChangeError,
    AuthenticatedSession,
@@ -22,6 +28,8 @@ from app.services.auth import (
    create_session,
    revoke_session,
 )
+from app.services import login_throttle
+from app.services import totp as totp_service

 logger = logging.getLogger(__name__)

@@ -46,9 +54,26 @@ def get_session(
    return _build_session_response(auth)


+def _get_client_ip(request: Request, *, trust_forwarded_for: bool) -> str:
+    """Extract the client IP address from the request.
+
+    When ``trust_forwarded_for`` is True (reverse-proxy deployments) the
+    left-most value from the ``X-Forwarded-For`` header is used.  Otherwise the
+    direct socket IP (``request.client.host``) is used.
+    """
+    if trust_forwarded_for:
+        xff = request.headers.get("X-Forwarded-For", "")
+        if xff:
+            return xff.split(",")[0].strip()
+    if request.client is not None:
+        return request.client.host
+    return "unknown"
+
+
@router.post("/auth/login", response_model=SessionResponse)
 def post_login(
    body: LoginRequest,
+    request: Request,
    response: Response,
    db: Session = Depends(get_db),
    settings: Settings = Depends(get_app_settings),
@@ -58,15 +83,67 @@ def post_login(

    On success, sets an HttpOnly session cookie and returns the session user + CSRF token.
    On failure, returns 401 with no cookie set.
+    Repeated failures trigger exponential back-off (429 + Retry-After).
    No X-CSRF-Token required (unauthenticated endpoint).
    """
+    client_ip = _get_client_ip(request, trust_forwarded_for=settings.auth_trust_forwarded_for)
+
+    # --- Throttle check (before any password verification) ---
+    if settings.auth_login_throttle_enabled:
+        wait_seconds = login_throttle.check_and_get_wait(
+            db, ip=client_ip, username=body.username
+        )
+        if wait_seconds > 0:
+            raise HTTPException(
+                status_code=status.HTTP_429_TOO_MANY_REQUESTS,
+                detail="too many failed login attempts; please try again later",
+                headers={"Retry-After": str(wait_seconds)},
+            )
+
+    # --- Password verification ---
    user = authenticate_user(db, username=body.username, password=body.password)
    if user is None:
+        if settings.auth_login_throttle_enabled:
+            login_throttle.register_failure(db, ip=client_ip, username=body.username)
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="invalid username or password",
        )

+    # --- TOTP second-factor check (only when TOTP is enabled for the user) ---
+    if user.totp_enabled:
+        if not body.totp_code:
+            # Password correct but no TOTP code supplied: signal the front-end to
+            # prompt for the second factor.  Do NOT issue a session.
+            # Deliberate: this is a normal two-step protocol step from a legitimate
+            # user — we do NOT register a throttle failure here.  The attacker must
+            # already have the correct password to reach this branch, and counting
+            # each normal first-step as a failure would risk locking out the real
+            # admin on every login attempt.
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail={"totp_required": True},
+            )
+
+        # TOTP code supplied — verify against time-based code or a recovery code.
+        totp_ok = totp_service.verify_totp_code(user, body.totp_code)
+        if not totp_ok:
+            totp_ok = totp_service.verify_recovery_code(db, user=user, code=body.totp_code)
+
+        if not totp_ok:
+            # Second-factor failure is an active attack signal — register failure
+            # so that repeated wrong TOTP/recovery-code guesses trigger back-off.
+            if settings.auth_login_throttle_enabled:
+                login_throttle.register_failure(db, ip=client_ip, username=body.username)
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="invalid username or password",
+            )
+
+    # --- Success: clear back-off state and issue session ---
+    if settings.auth_login_throttle_enabled:
+        login_throttle.clear(db, ip=client_ip, username=body.username)
+
    auth_session, raw_token = create_session(db, user=user, settings=settings)
    logger.info("Created API authenticated session for user '%s'", user.username)

@@ -139,3 +216,109 @@ def post_change_password(

    logger.info("Password updated for user '%s'", auth.user.username)
    return Response(status_code=status.HTTP_204_NO_CONTENT)
+
+
+# ---------------------------------------------------------------------------
+# TOTP endpoints (M4-T05)
+# ---------------------------------------------------------------------------
+
+
+@router.post("/auth/totp/setup", response_model=TotpSetupResponse)
+def post_totp_setup(
+    db: Session = Depends(get_db),
+    settings: Settings = Depends(get_app_settings),
+    auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> TotpSetupResponse:
+    """
+    Generate a new pending TOTP secret, otpauth URI, and one-time recovery codes.
+
+    The secret is stored in the DB but TOTP is NOT yet enabled (totp_enabled stays
+    False until the user confirms with POST /api/auth/totp/enable).
+
+    Recovery codes are returned here as plaintext exactly once; their Argon2 hashes
+    are persisted immediately so enable only needs to flip the enabled flag.
+
+    Repeating this call replaces any prior pending secret and regenerates codes.
+
+    Requires: session cookie + X-CSRF-Token.
+    """
+    secret, otpauth_uri, recovery_codes = totp_service.setup(
+        db,
+        user=auth.user,
+        issuer=settings.effective_totp_issuer,
+    )
+    return TotpSetupResponse(
+        secret=secret,
+        otpauth_uri=otpauth_uri,
+        recovery_codes=recovery_codes,
+    )
+
+
+@router.post("/auth/totp/enable", status_code=status.HTTP_204_NO_CONTENT)
+def post_totp_enable(
+    body: TotpEnableRequest,
+    db: Session = Depends(get_db),
+    auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> Response:
+    """
+    Enable TOTP by confirming with the current 6-digit code from the authenticator app.
+
+    Requires a prior call to POST /api/auth/totp/setup (so that a pending secret
+    exists).  On success, totp_enabled becomes True.
+
+    Returns 400 if the code is wrong or there is no pending secret.
+    Requires: session cookie + X-CSRF-Token.
+    """
+    ok = totp_service.enable(db, user=auth.user, code=body.code)
+    if not ok:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="invalid TOTP code or no pending setup",
+        )
+    return Response(status_code=status.HTTP_204_NO_CONTENT)
+
+
+@router.post("/auth/totp/disable", status_code=status.HTTP_204_NO_CONTENT)
+def post_totp_disable(
+    body: TotpDisableRequest,
+    db: Session = Depends(get_db),
+    auth: AuthenticatedSession = Depends(require_session),
+    _csrf: None = Depends(require_csrf),
+) -> Response:
+    """
+    Disable TOTP.  The caller must provide exactly one of:
+    - ``password``: the user's current login password, OR
+    - ``code``: the current 6-digit TOTP code.
+
+    On success: totp_enabled=False, totp_secret cleared, all recovery codes deleted.
+    Returns 400 if neither credential matches or neither is provided.
+    Requires: session cookie + X-CSRF-Token.
+    """
+    ok = totp_service.disable(
+        db,
+        user=auth.user,
+        password=body.password,
+        code=body.code,
+    )
+    if not ok:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="invalid credential; provide a valid password or TOTP code",
+        )
+    return Response(status_code=status.HTTP_204_NO_CONTENT)
+
+
+@router.get("/auth/totp", response_model=TotpStatusResponse)
+def get_totp_status(
+    auth: AuthenticatedSession = Depends(require_session),
+) -> TotpStatusResponse:
+    """
+    Return the current TOTP status for the authenticated user.
+
+    Response contains only ``{"enabled": bool}``.
+    Secret and recovery codes are NEVER returned here.
+    Requires: session cookie only (no CSRF — read-only).
+    """
+    return TotpStatusResponse(enabled=auth.user.totp_enabled)
@@ -37,6 +37,42 @@ class Settings(BaseSettings):
    auth_session_cookie_name: str = "home_automation_session"
    auth_session_ttl_hours: int = 12
    auth_cookie_secure_override: bool | None = True
+    auth_login_throttle_enabled: bool = True
+    auth_trust_forwarded_for: bool = False
+    auth_totp_issuer: str = ""  # defaults to app_name when empty
+
+    # Modbus polling — global kill-switch (CONFIG_FIELDS registered in T08).
+    # Off by default: polling is opt-in so a fresh deploy writes no modbus_reading
+    # rows until the admin explicitly enables it (matches mqtt/discovery defaults).
+    modbus_polling_enabled: bool = False
+
+    # MQTT broker connection (T08 wires into CONFIG_FIELDS/UI; T10 builds the client).
+    mqtt_enabled: bool = False
+    mqtt_broker_host: str = ""
+    mqtt_broker_port: int = 1883
+    mqtt_username: str = ""
+    mqtt_password: str = ""
+    mqtt_tls_enabled: bool = False
+
+    # Home Assistant MQTT Discovery (T08 wires into CONFIG_FIELDS/UI; T11 does publishing).
+    ha_discovery_enabled: bool = False
+    ha_discovery_prefix: str = "homeassistant"
+    # State/availability topics use a separate prefix so they live outside the HA discovery
+    # namespace.  HA still receives state via the state_topic declared in the discovery config.
+    ha_state_topic_prefix: str = "home_automation"
+
+    # DSMR smart-meter ingest via MQTT (M6; default off — opt-in).
+    # Subscribe to dsmr_mqtt_topic when dsmr_ingest_enabled=True.
+    dsmr_ingest_enabled: bool = False
+    dsmr_mqtt_topic: str = "dsmr/json"
+    dsmr_sample_interval_s: int = 10
+    # DSMR dual-tariff topic: publishes "1" (dal/off-peak) or "2" (normal/peak).
+    # Empty string = do not subscribe (tariff-aware pricing disabled).
+    dsmr_tariff_topic: str = "dsmr/meter-stats/electricity_tariff"
+
+    # Tibber dynamic pricing credentials (M6; only used when active contract kind=tibber).
+    tibber_api_token: str = ""
+    tibber_home_id: str = ""

    model_config = SettingsConfigDict(
        env_file=".env",
@@ -86,6 +122,12 @@ class Settings(BaseSettings):
            return self.auth_cookie_secure_override
        return not self.is_development

+    @computed_field
+    @property
+    def effective_totp_issuer(self) -> str:
+        """The issuer label shown in Authenticator apps. Falls back to app_name."""
+        return self.auth_totp_issuer.strip() or self.app_name
+

@lru_cache
 def get_settings() -> Settings:
@@ -28,6 +28,7 @@ def _get_engine(database_url: str) -> Engine:
        def _enable_sqlite_wal(dbapi_connection, _connection_record):
            cursor = dbapi_connection.cursor()
            cursor.execute("PRAGMA journal_mode=WAL")
+            cursor.execute("PRAGMA foreign_keys=ON")
            cursor.close()

    return engine
@@ -0,0 +1,869 @@
+"""Expose framework: ExposableEntity, provider protocol, and build_catalog.
+
+This module defines:
+
+- ``ExposableEntity`` — a dataclass describing one publishable MQTT/HA entity.
+- Provider protocol — a simple callable ``(session) -> list[ExposableEntity]``.
+- A provider registry and registration helper.
+- ``build_catalog(session)`` — merges all registered providers' entities with
+  per-key toggle state from the ``exposed_entity_toggle`` table.
+
+Design notes
+------------
+- **No over-engineering**: providers are plain callables, not abstract base
+  classes.  This project is personal / single-user; keep it flat.
+- **Key stability**: entity keys MUST be derived from device uuid + metric key
+  (e.g. ``"modbus.<uuid>.voltage"``), never from auto-increment IDs.  Stable
+  keys mean the toggle table survives device removal/re-addition without drift.
+- **Metadata from profile**: the modbus provider reads ``device_class``,
+  ``unit``, and ``component`` directly from the YAML profile's ``metrics[]``
+  rather than maintaining a separate mapping.
+- **value_getter**: a callable ``() -> object | None`` or ``None`` if not yet
+  implemented (T11 will wire real getters).  Presence of the field lets T11
+  call it without changing the dataclass interface.
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass, field
+from typing import Any, Callable, Optional, Protocol
+
+from sqlalchemy.orm import Session
+
+logger = logging.getLogger(__name__)
+
+
+# ---------------------------------------------------------------------------
+# ExposableEntity
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class DeviceInfo:
+    """Grouping metadata that maps an entity to a logical HA device.
+
+    ``identifiers`` corresponds to ``device.identifiers`` in HA Discovery
+    config — a stable tuple used to group entities under one device card.
+    ``name`` is the human-readable device name (friendly_name).
+    """
+
+    identifiers: tuple[str, ...]
+    """Stable identifiers for HA device grouping (e.g. ``("modbus", "<uuid>")``).
+
+    These must not change over the device lifetime; they anchor the HA device
+    card even when friendly_name changes.
+    """
+
+    name: str
+    """Human-readable device name (may change; triggers HA discovery re-publish)."""
+
+    provides_availability: bool = True
+    """Whether this device publishes an availability ("online"/"offline") heartbeat.
+
+    When True (the default — e.g. Modbus devices, which have an ``online``
+    binary_sensor driving availability), the HA Discovery config for each entity
+    declares an ``availability`` topic and HA marks the entity unavailable until
+    "online" is published.
+
+    When False (e.g. the energy-cost device, which has only sensors and no
+    heartbeat source), the config omits ``availability`` so HA treats the entity
+    as *always available* and shows its state as soon as one arrives.  Without
+    this, such entities would stay perpetually ``unavailable`` in HA even though
+    their state is being published.
+    """
+
+
+@dataclass
+class ExposableEntity:
+    """One publishable entity in the MQTT / HA Discovery expose framework.
+
+    Fields
+    ------
+    key
+        Stable unique identifier for this entity.  Used as the toggle table
+        key and as part of the HA Discovery ``unique_id`` derivation.
+        Convention: ``"<provider>.<device_uuid>.<metric_key>"``,
+        e.g. ``"modbus.abc123.voltage"`` or ``"modbus.abc123.online"``.
+
+    component
+        HA MQTT component type: ``"sensor"``, ``"binary_sensor"``, ``"switch"``, etc.
+
+    device
+        Grouping info (DeviceInfo) that determines which HA device card this
+        entity belongs to.
+
+    device_class
+        HA ``device_class`` string (e.g. ``"voltage"``, ``"power"``, ``"None"``).
+        Empty string or ``None`` means no device_class (e.g. for the online sensor).
+
+    unit
+        Physical unit string (e.g. ``"V"``, ``"A"``, ``"kWh"``).
+        Empty string for dimensionless.
+
+    name
+        Human-readable entity label (friendly display name, may include device
+        context, e.g. ``"SDM120 Voltage"``).
+
+    value_getter
+        Optional callable ``(session) -> object | None`` that returns the current
+        entity value given an open SQLAlchemy session.  ``None`` means "not yet
+        wired".  T11 calls this to obtain the current state before publishing.
+        Signature: ``Callable[[Session], Any]``.
+
+    state_class
+        HA ``state_class`` string (e.g. ``"measurement"``, ``"total_increasing"``).
+        ``None`` means not set.
+    """
+
+    key: str
+    component: str
+    device: DeviceInfo
+    device_class: Optional[str]
+    unit: str
+    name: str
+    value_getter: Optional[Callable[["Session"], Any]] = field(default=None, repr=False)
+    state_class: Optional[str] = None
+
+
+# ---------------------------------------------------------------------------
+# Provider protocol
+# ---------------------------------------------------------------------------
+
+
+class EntityProvider(Protocol):
+    """Protocol for entity provider callables.
+
+    A provider is any callable that accepts a ``Session`` and returns a list
+    of ``ExposableEntity`` objects.  Using a Protocol (not ABC) keeps the
+    implementation lightweight — any matching callable qualifies.
+    """
+
+    def __call__(self, session: Session) -> list[ExposableEntity]: ...
+
+
+# ---------------------------------------------------------------------------
+# Provider registry
+# ---------------------------------------------------------------------------
+
+_REGISTRY: list[EntityProvider] = []
+
+
+def register_provider(provider: EntityProvider) -> EntityProvider:
+    """Register an entity provider.
+
+    Can be used as a decorator::
+
+        @register_provider
+        def my_provider(session: Session) -> list[ExposableEntity]:
+            ...
+
+    Or called directly::
+
+        register_provider(my_provider)
+
+    Returns the provider unchanged (for decorator compatibility).
+    """
+    _REGISTRY.append(provider)
+    return provider
+
+
+def get_providers() -> list[EntityProvider]:
+    """Return a snapshot of the currently registered providers."""
+    return list(_REGISTRY)
+
+
+# ---------------------------------------------------------------------------
+# Catalog builder
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class CatalogEntry:
+    """An entity from the catalog, enriched with its current toggle state."""
+
+    entity: ExposableEntity
+    enabled: bool
+    """True if this entity is currently enabled in the toggle table."""
+
+
+def build_catalog(session: Session) -> list[CatalogEntry]:
+    """Enumerate all entities from registered providers and attach toggle state.
+
+    For each entity key, the toggle state is looked up in ``exposed_entity_toggle``.
+    Entities with no toggle row default to ``enabled=False``.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session for DB access.
+
+    Returns
+    -------
+    list[CatalogEntry]
+        All entities from all registered providers, each paired with its
+        current ``enabled`` state.
+    """
+    from app.models.expose import ExposedEntityToggle  # local import to avoid circular
+
+    # Collect all entities from all providers.
+    all_entities: list[ExposableEntity] = []
+    for provider in _REGISTRY:
+        try:
+            entities = provider(session)
+            all_entities.extend(entities)
+        except Exception:
+            logger.exception("Provider %r raised an error; skipping its entities", provider)
+
+    if not all_entities:
+        return []
+
+    # Load all toggle rows in one query for efficiency.
+    keys = [e.key for e in all_entities]
+    toggle_rows = session.query(ExposedEntityToggle).filter(
+        ExposedEntityToggle.key.in_(keys)
+    ).all()
+    toggle_map: dict[str, bool] = {row.key: row.enabled for row in toggle_rows}
+
+    return [
+        CatalogEntry(entity=entity, enabled=toggle_map.get(entity.key, False))
+        for entity in all_entities
+    ]
+
+
+# ---------------------------------------------------------------------------
+# Modbus provider
+# ---------------------------------------------------------------------------
+
+
+def _modbus_provider(session: Session) -> list[ExposableEntity]:
+    """Enumerate ExposableEntity objects for all enabled Modbus devices.
+
+    For each enabled ``ModbusDevice``:
+    - Loads its YAML profile.
+    - Produces one ``sensor`` entity per metric in ``profile.metrics``
+      (device_class / unit / component taken from the metric spec).
+    - Produces one ``binary_sensor`` entity named "online" (derived from
+      ``device.last_poll_ok``).
+
+    Entity keys follow the pattern ``"modbus.<uuid>.<metric_key>"``, which is
+    stable across device renames and DB rebuilds.
+    """
+    from app.models.modbus import ModbusDevice  # local import
+    from app.integrations.modbus.profiles import (
+        load_profile,
+        ProfileNotFoundError,
+        ProfileValidationError,
+    )
+
+    devices: list[ModbusDevice] = session.query(ModbusDevice).filter(
+        ModbusDevice.enabled.is_(True)
+    ).all()
+
+    entities: list[ExposableEntity] = []
+
+    for device in devices:
+        device_info = DeviceInfo(
+            identifiers=("modbus", device.uuid),
+            name=device.friendly_name,
+        )
+
+        # Load the profile to get metric metadata.
+        try:
+            profile = load_profile(device.profile)
+        except (ProfileNotFoundError, ProfileValidationError) as exc:
+            logger.warning(
+                "Skipping device %r (uuid=%s): cannot load profile %r: %s",
+                device.friendly_name,
+                device.uuid,
+                device.profile,
+                exc,
+            )
+            continue
+
+        # One sensor entity per profile metric.
+        for metric in profile.metrics:
+            entity_key = f"modbus.{device.uuid}.{metric.key}"
+
+            # Capture device id and metric key for the value_getter closure.
+            # The getter queries the most recent ModbusReading for this device
+            # and extracts the metric value from its payload.
+            _device_id = device.id
+            _metric_key = metric.key
+
+            def _make_value_getter(
+                dev_id: int, m_key: str
+            ) -> Callable[["Session"], Any]:
+                """Return a getter that fetches the latest reading value from DB."""
+                def _getter(sess: "Session") -> Any:
+                    from app.models.modbus import ModbusReading
+                    from sqlalchemy import desc
+
+                    reading = (
+                        sess.query(ModbusReading)
+                        .filter(ModbusReading.device_id == dev_id)
+                        .order_by(desc(ModbusReading.recorded_at))
+                        .first()
+                    )
+                    if reading is None:
+                        return None
+                    return reading.payload.get(m_key)
+
+                return _getter
+
+            entities.append(
+                ExposableEntity(
+                    key=entity_key,
+                    component=metric.ha_component,
+                    device=device_info,
+                    device_class=metric.device_class or None,
+                    unit=metric.unit,
+                    name=f"{device.friendly_name} {metric.key.replace('_', ' ').title()}",
+                    value_getter=_make_value_getter(_device_id, _metric_key),
+                    state_class=metric.state_class,
+                )
+            )
+
+        # One binary_sensor entity for device "online" status.
+        online_key = f"modbus.{device.uuid}.online"
+        _dev_id_online = device.id
+
+        def _make_online_getter(dev_id: int) -> Callable[["Session"], Any]:
+            """Return a getter that reports the device online status from DB."""
+            def _getter(sess: "Session") -> Any:
+                from app.models.modbus import ModbusDevice
+
+                dev = sess.query(ModbusDevice).filter(
+                    ModbusDevice.id == dev_id
+                ).first()
+                if dev is None:
+                    return None
+                # Map last_poll_ok to HA binary_sensor payload strings.
+                if dev.last_poll_ok is True:
+                    return "ON"
+                return "OFF"
+
+            return _getter
+
+        entities.append(
+            ExposableEntity(
+                key=online_key,
+                component="binary_sensor",
+                device=device_info,
+                device_class="connectivity",
+                unit="",
+                name=f"{device.friendly_name} Online",
+                value_getter=_make_online_getter(_dev_id_online),
+                state_class=None,
+            )
+        )
+
+    return entities
+
+
+# Register the modbus provider at module load time.
+register_provider(_modbus_provider)
+
+
+# ---------------------------------------------------------------------------
+# Energy Cost provider
+# ---------------------------------------------------------------------------
+
+
+def _energy_cost_provider(session: Session) -> list[ExposableEntity]:
+    """Enumerate ExposableEntity objects for the energy cost subsystem.
+
+    Produces 6 sensor entities grouped under a single HA device whose identity
+    is anchored to the **current active electricity meter**:
+
+    - ``buy_price_now``         — current effective buy price (EUR/kWh or local currency).
+    - ``sell_price_now``        — current effective sell price (EUR/kWh or local currency).
+    - ``import_cost_total``     — cumulative import cost (total, monetary).
+    - ``export_revenue_total``  — cumulative export revenue (total, monetary).
+    - ``import_cost_today``     — today's import cost (total_increasing, monetary).
+    - ``export_revenue_today``  — today's export revenue (total_increasing, monetary).
+
+    Active meter requirement
+    ------------------------
+    **If no active electricity meter exists, the provider returns ``[]``.**
+    No energy-cost entities are exposed to HA until a meter has been declared.
+    This prevents spurious sensor creation with an undefined device identity.
+
+    HA device identity (换表 → 新 sensor)
+    --------------------------------------
+    ``identifiers[1]`` is set to the active meter's **uuid** (not the fixed
+    string ``"energy-cost"``).  ``ha_discovery.py`` uses ``identifiers[1]`` as
+    the MQTT node_id and as part of the ``unique_id`` for every entity.
+    Declaring a new active electricity meter produces a new uuid → new node_id /
+    unique_id → HA creates a brand-new sensor, cleanly isolating post-swap data.
+
+    Entity key stability
+    --------------------
+    Entity keys remain the fixed stable strings (``"energy.buy_price_now"`` etc.),
+    **not** derived from the meter uuid.  The ``exposed_entity_toggle`` table uses
+    keys as its primary handle; keeping them stable means toggled-on entities stay
+    enabled after a meter swap without requiring the user to re-tick them.
+
+    Current-price algorithm (source-agnostic, with fallback)
+    ---------------------------------------------------------
+    Strategy A: read the ``pricing`` snapshot from the most recent non-degraded
+    ``energy_cost_period`` row.
+
+    - For ``kind="tibber"``: the snapshot contains ``"buy"`` and ``"sell"`` keys
+      (per-unit prices in the contract currency).
+    - For ``kind="manual"``: ``"buy_normal"`` and ``"sell_normal"`` are used as
+      representative effective per-unit prices.  (Both tariff-slot prices differ
+      only by the base rate; energy_tax and ODE are the same for both, so
+      buy_normal is the higher/conservative single representative value.)
+
+    When no non-degraded period exists or the pricing snapshot lacks the
+    expected keys, ``value_getter`` returns ``None`` (``publish_states``
+    skips None values automatically).
+
+    Cumulative totals
+    -----------------
+    ``SUM(import_cost)`` and ``SUM(export_revenue)`` over **all non-degraded**
+    ``energy_cost_period`` rows within the current meter's window.  Degraded rows
+    carry 0 costs and are excluded to avoid double-counting when they are later
+    overwritten by real values.
+
+    Currency
+    --------
+    Taken from the most recent non-degraded period's ``currency`` column.
+    Falls back to ``"EUR"`` when no such row exists.
+
+    Key convention
+    --------------
+    Fixed stable string keys (not derived from any mutable field or DB id):
+      - ``"energy.buy_price_now"``
+      - ``"energy.sell_price_now"``
+      - ``"energy.import_cost_total"``
+      - ``"energy.export_revenue_total"``
+      - ``"energy.import_cost_today"``
+      - ``"energy.export_revenue_today"``
+
+    DeviceInfo identifiers
+    ----------------------
+    **Two-element tuple** ``("energy-cost", meter.uuid)`` so that
+    ``ha_discovery.py``'s ``entity.device.identifiers[1]`` resolves to the
+    meter uuid (used as the MQTT node_id and unique_id seed throughout).
+    """
+    from app.models.energy import EnergyCostPeriod, Meter  # local import to avoid circular
+    from sqlalchemy import select
+
+    # --- Require an active electricity meter; return [] if none exists ---
+    # Using an inline query (ended_at IS NULL) rather than a service-layer helper
+    # to avoid a new public dependency and remain consistent with the value_getter
+    # implementations below (which use the same inline pattern).
+    active_meter: Meter | None = session.execute(
+        select(Meter)
+        .where(
+            Meter.commodity == "electricity",
+            Meter.ended_at.is_(None),
+        )
+        .limit(1)
+    ).scalar_one_or_none()
+
+    if active_meter is None:
+        # No active electricity meter → do not expose any energy-cost entities.
+        # HA will not see these sensors until a meter is declared.
+        return []
+
+    # --- Determine currency from the latest non-degraded row ---
+
+    latest_period: EnergyCostPeriod | None = (
+        session.query(EnergyCostPeriod)
+        .filter(EnergyCostPeriod.degraded.is_(False))
+        .order_by(EnergyCostPeriod.period_start.desc())
+        .first()
+    )
+
+    currency: str = "EUR"
+    if latest_period is not None and latest_period.currency:
+        currency = latest_period.currency
+
+    # --- Shared DeviceInfo anchored to the active meter's uuid ---
+    # identifiers[1] = meter.uuid drives the MQTT node_id and unique_id in
+    # ha_discovery.py.  Swapping the meter produces a new uuid → new HA sensor.
+    # provides_availability=False: the energy-cost device has only sensors and no
+    # online/offline heartbeat, so its entities must be "always available" in HA.
+    # (Otherwise HA shows them unavailable despite state being published.)
+    device_info = DeviceInfo(
+        identifiers=("energy-cost", active_meter.uuid),
+        name=active_meter.label,
+        provides_availability=False,
+    )
+
+    # --- value_getter: current buy price ---
+
+    def _make_buy_price_getter() -> Callable[["Session"], Any]:
+        """Return a getter for the current buy price per kWh.
+
+        For ``kind="manual"`` contracts the getter selects the price slot that
+        matches the current DSMR electricity tariff:
+
+        - tariff == 1 (dal / off-peak)  → ``buy_dal``
+        - tariff == 2 (normal / peak)   → ``buy_normal``
+        - tariff is None / unknown       → ``buy_normal`` (safe fallback = current status quo)
+
+        For ``kind="tibber"`` (hourly dynamic pricing) the tariff slot is not
+        applicable; the getter always uses the ``buy`` key from the snapshot.
+        """
+        def _getter(sess: "Session") -> Any:
+            from app.models.energy import EnergyCostPeriod as _ECP
+            from app.services.dsmr_ingest import get_current_tariff
+
+            period = (
+                sess.query(_ECP)
+                .filter(_ECP.degraded.is_(False))
+                .order_by(_ECP.period_start.desc())
+                .first()
+            )
+            if period is None or not period.pricing:
+                return None
+            snap = period.pricing
+            kind = snap.get("kind")
+            if kind == "tibber":
+                raw = snap.get("buy")
+            elif kind == "manual":
+                tariff = get_current_tariff()
+                if tariff == 1:
+                    raw = snap.get("buy_dal")
+                else:
+                    # tariff == 2, None, or any unexpected value → normal (peak) rate.
+                    raw = snap.get("buy_normal")
+            else:
+                # Unknown kind — attempt common keys gracefully.
+                raw = snap.get("buy") or snap.get("buy_normal")
+            if raw is None:
+                return None
+            try:
+                return float(raw)
+            except (TypeError, ValueError):
+                return None
+
+        return _getter
+
+    # --- value_getter: current sell price ---
+
+    def _make_sell_price_getter() -> Callable[["Session"], Any]:
+        """Return a getter for the current sell price per kWh.
+
+        For ``kind="manual"`` contracts the getter selects the price slot that
+        matches the current DSMR electricity tariff:
+
+        - tariff == 1 (dal / off-peak)  → ``sell_dal``
+        - tariff == 2 (normal / peak)   → ``sell_normal``
+        - tariff is None / unknown       → ``sell_normal`` (safe fallback = current status quo)
+
+        For ``kind="tibber"`` the tariff slot is not applicable; always uses ``sell``.
+        """
+        def _getter(sess: "Session") -> Any:
+            from app.models.energy import EnergyCostPeriod as _ECP
+            from app.services.dsmr_ingest import get_current_tariff
+
+            period = (
+                sess.query(_ECP)
+                .filter(_ECP.degraded.is_(False))
+                .order_by(_ECP.period_start.desc())
+                .first()
+            )
+            if period is None or not period.pricing:
+                return None
+            snap = period.pricing
+            kind = snap.get("kind")
+            if kind == "tibber":
+                raw = snap.get("sell")
+            elif kind == "manual":
+                tariff = get_current_tariff()
+                if tariff == 1:
+                    raw = snap.get("sell_dal")
+                else:
+                    # tariff == 2, None, or any unexpected value → normal (peak) rate.
+                    raw = snap.get("sell_normal")
+            else:
+                raw = snap.get("sell") or snap.get("sell_normal")
+            if raw is None:
+                return None
+            try:
+                return float(raw)
+            except (TypeError, ValueError):
+                return None
+
+        return _getter
+
+    # --- value_getter: cumulative import cost (incl. standing charges) ---
+
+    def _make_import_cost_getter() -> Callable[["Session"], Any]:
+        """Return a getter for the cumulative import cost plus prorated standing charges.
+
+        D2 (M7): anchor = current active electricity meter's ``started_at``.
+        After a meter swap the cumulative resets to zero for the new meter —
+        old-meter periods have ``period_start < new_meter.started_at`` and fall
+        outside the [anchor, now) window, so they are naturally excluded.
+        Cross-meter boundary periods are already degraded and also excluded.
+
+        No active electricity meter → returns None (cannot anchor; safer than
+        returning a stale or wrong value).  The check is done via an inline
+        query (``ended_at IS NULL``) rather than ``meter_at(now)`` to be robust
+        against the edge case where the active meter's ``started_at`` is in the
+        future (``meter_at(now)`` would return None in that scenario).
+
+        No non-degraded periods at all → returns None (has_data guard).
+
+        No active contract → ``summarize`` still runs but fixed_costs = 0;
+        the return value is the pure metered sum within the current meter window.
+        This is consistent with D2: the anchor is the meter, not the contract.
+
+            value = summarize(anchor → now).metered_import + summarize(anchor → now).fixed_costs
+        """
+        def _getter(sess: "Session") -> Any:
+            from datetime import UTC, datetime as _dt
+            from app.models.energy import EnergyCostPeriod as _ECP, Meter as _Meter
+            from app.services.energy_cost import summarize as _summarize
+            from sqlalchemy import func as _func, select as _select
+
+            # Quick check: any non-degraded period at all?
+            has_data = sess.query(_func.sum(_ECP.import_cost)).filter(
+                _ECP.degraded.is_(False)
+            ).scalar()
+            if has_data is None:
+                return None
+
+            # D2: anchor = active electricity meter's started_at.
+            # Inline query (ended_at IS NULL) is more robust than meter_at(now)
+            # because it avoids the edge case where started_at is in the future.
+            active_meter = sess.execute(
+                _select(_Meter)
+                .where(
+                    _Meter.commodity == "electricity",
+                    _Meter.ended_at.is_(None),
+                )
+                .limit(1)
+            ).scalar_one_or_none()
+
+            if active_meter is None:
+                # No active electricity meter — cannot anchor; return None.
+                return None
+
+            from app.services.contracts import _as_utc as _cu
+            anchor_utc = _cu(active_meter.started_at)
+            now_utc = _dt.now(UTC)
+
+            result = _summarize(sess, anchor_utc, now_utc)
+            return result["metered_import"] + result["fixed_costs"]
+
+        return _getter
+
+    # --- value_getter: cumulative export revenue (incl. tax credit) ---
+
+    def _make_export_revenue_getter() -> Callable[["Session"], Any]:
+        """Return a getter for the cumulative export revenue plus prorated tax credit.
+
+        D2 (M7): anchor = current active electricity meter's ``started_at``.
+        Same reasoning as the import cost getter — see its docstring.
+
+            value = summarize(anchor → now).metered_export + summarize(anchor → now).credits
+
+        Returns None when no non-degraded period exists or no active electricity meter.
+        """
+        def _getter(sess: "Session") -> Any:
+            from datetime import UTC, datetime as _dt
+            from app.models.energy import EnergyCostPeriod as _ECP, Meter as _Meter
+            from app.services.energy_cost import summarize as _summarize
+            from sqlalchemy import func as _func, select as _select
+
+            # Quick check: any non-degraded period at all?
+            has_data = sess.query(_func.sum(_ECP.export_revenue)).filter(
+                _ECP.degraded.is_(False)
+            ).scalar()
+            if has_data is None:
+                return None
+
+            # D2: anchor = active electricity meter's started_at.
+            active_meter = sess.execute(
+                _select(_Meter)
+                .where(
+                    _Meter.commodity == "electricity",
+                    _Meter.ended_at.is_(None),
+                )
+                .limit(1)
+            ).scalar_one_or_none()
+
+            if active_meter is None:
+                # No active electricity meter — cannot anchor; return None.
+                return None
+
+            from app.services.contracts import _as_utc as _cu
+            anchor_utc = _cu(active_meter.started_at)
+            now_utc = _dt.now(UTC)
+
+            result = _summarize(sess, anchor_utc, now_utc)
+            return result["metered_export"] + result["credits"]
+
+        return _getter
+
+    # --- value_getter: today's import cost (local-day window, resets at local midnight) ---
+
+    def _make_import_cost_today_getter() -> Callable[["Session"], Any]:
+        """Return a getter for today's import cost (metered + standing for today).
+
+        Window: [local today 00:00, local tomorrow 00:00) in UTC.
+        After local midnight the window rolls to the new day → value resets to that
+        day's running cost, implementing "resets at local midnight" semantics for HA.
+
+        Uses timezone module via module-attribute access to preserve monkeypatch safety.
+        Returns None when no non-degraded period exists or no active contract.
+        """
+        def _getter(sess: "Session") -> Any:
+            from app.services.contracts import active_contract_versions
+            from app.models.energy import EnergyCostPeriod as _ECP
+            from app.services.energy_cost import summarize as _summarize
+            from app.services import timezone as _tz_mod
+            from sqlalchemy import func as _func
+            from datetime import timedelta as _td
+
+            # Quick check: any non-degraded period at all?
+            has_data = sess.query(_func.sum(_ECP.import_cost)).filter(
+                _ECP.degraded.is_(False)
+            ).scalar()
+            if has_data is None:
+                return None
+
+            versions = active_contract_versions(sess)
+            if not versions:
+                return None
+
+            # Today's window in UTC, using monkeypatch-safe module attribute calls.
+            today_local = _tz_mod.local_now().date()
+            tomorrow_local = today_local + _td(days=1)
+            today_start_utc = _tz_mod.local_midnight_utc(today_local)
+            tomorrow_start_utc = _tz_mod.local_midnight_utc(tomorrow_local)
+
+            result = _summarize(sess, today_start_utc, tomorrow_start_utc)
+            return result["metered_import"] + result["fixed_costs"]
+
+        return _getter
+
+    # --- value_getter: today's export revenue (local-day window, resets at local midnight) ---
+
+    def _make_export_revenue_today_getter() -> Callable[["Session"], Any]:
+        """Return a getter for today's export revenue (metered + tax credit for today).
+
+        Same window semantics as import_cost_today.
+        Returns None when no non-degraded period exists or no active contract.
+        """
+        def _getter(sess: "Session") -> Any:
+            from app.services.contracts import active_contract_versions
+            from app.models.energy import EnergyCostPeriod as _ECP
+            from app.services.energy_cost import summarize as _summarize
+            from app.services import timezone as _tz_mod
+            from sqlalchemy import func as _func
+            from datetime import timedelta as _td
+
+            # Quick check: any non-degraded period at all?
+            has_data = sess.query(_func.sum(_ECP.export_revenue)).filter(
+                _ECP.degraded.is_(False)
+            ).scalar()
+            if has_data is None:
+                return None
+
+            versions = active_contract_versions(sess)
+            if not versions:
+                return None
+
+            today_local = _tz_mod.local_now().date()
+            tomorrow_local = today_local + _td(days=1)
+            today_start_utc = _tz_mod.local_midnight_utc(today_local)
+            tomorrow_start_utc = _tz_mod.local_midnight_utc(tomorrow_local)
+
+            result = _summarize(sess, today_start_utc, tomorrow_start_utc)
+            return result["metered_export"] + result["credits"]
+
+        return _getter
+
+    # Price unit string: "<currency>/kWh"
+    price_unit = f"{currency}/kWh"
+
+    entities: list[ExposableEntity] = [
+        ExposableEntity(
+            key="energy.buy_price_now",
+            component="sensor",
+            device=device_info,
+            device_class=None,
+            unit=price_unit,
+            name="Energy Buy Price Now",
+            value_getter=_make_buy_price_getter(),
+            state_class="measurement",
+        ),
+        ExposableEntity(
+            key="energy.sell_price_now",
+            component="sensor",
+            device=device_info,
+            device_class=None,
+            unit=price_unit,
+            name="Energy Sell Price Now",
+            value_getter=_make_sell_price_getter(),
+            state_class="measurement",
+        ),
+        ExposableEntity(
+            key="energy.import_cost_total",
+            component="sensor",
+            device=device_info,
+            device_class="monetary",
+            unit=currency,
+            name="Energy Import Cost (incl. standing)",
+            value_getter=_make_import_cost_getter(),
+            state_class="total",
+        ),
+        ExposableEntity(
+            key="energy.export_revenue_total",
+            component="sensor",
+            device=device_info,
+            device_class="monetary",
+            unit=currency,
+            name="Energy Export Revenue (incl. tax credit)",
+            value_getter=_make_export_revenue_getter(),
+            state_class="total",
+        ),
+        # Daily entities: reset at local midnight, state_class=total_increasing.
+        #
+        # device_class=monetary is correct here.  The HA developer docs (long-term
+        # statistics section) prohibit MONETARY from being combined with
+        # state_class=measurement — they do NOT prohibit it with total or
+        # total_increasing.  monetary+total_increasing is valid (the cumulative
+        # entities above use monetary+total with no issue).
+        #
+        # total_increasing is appropriate because these daily quantities are
+        # non-negative (import/export metered cost ≥ 0, fixed standing fee/tax
+        # credit ≥ 0) and monotonically non-decreasing within any given local day.
+        # When the local midnight rolls over the value drops back to ~1 day's fixed
+        # fee; HA interprets that decrease as a new cycle, giving correct daily
+        # aggregation without any explicit last_reset pipeline.
+        ExposableEntity(
+            key="energy.import_cost_today",
+            component="sensor",
+            device=device_info,
+            device_class="monetary",
+            unit=currency,
+            name="Energy Import Cost Today (incl. standing)",
+            value_getter=_make_import_cost_today_getter(),
+            state_class="total_increasing",
+        ),
+        ExposableEntity(
+            key="energy.export_revenue_today",
+            component="sensor",
+            device=device_info,
+            device_class="monetary",
+            unit=currency,
+            name="Energy Export Revenue Today (incl. tax credit)",
+            value_getter=_make_export_revenue_today_getter(),
+            state_class="total_increasing",
+        ),
+    ]
+
+    return entities
+
+
+# Register the energy cost provider at module load time.
+register_provider(_energy_cost_provider)
@@ -0,0 +1 @@
+"""Modbus integration package — driver, profile loader, and decoder."""
@@ -0,0 +1,203 @@
+"""Modbus TCP driver — thin wrapper around pymodbus.
+
+This module provides a single public function ``read_blocks`` that performs
+one or more FC04 (Read Input Registers) block reads against a Modbus TCP
+gateway and returns a flat ``dict[register_address -> 16-bit_value]`` map.
+
+Design decisions
+----------------
+- **Only read function codes** (FC03/FC04) are exposed.  There is no write path.
+- float32 decoding uses ``struct.unpack('>f', ...)`` directly rather than the
+  pymodbus ``BinaryPayloadDecoder`` helper, which has had API churn across 3.x
+  releases.  Big-endian word order + big-endian byte order means the 4 raw bytes
+  are already in standard network (big-endian) order.
+- ``ModbusTcpClient`` is used in synchronous mode (``connect()`` / ``close()``).
+  The client is created fresh per call; this keeps the driver stateless and
+  avoids threading concerns at the cost of one TCP handshake per read cycle.
+  APScheduler jobs call this from a thread pool, so stateless is safer.
+- pymodbus 3.13.x uses ``device_id=`` as the slave-address keyword argument
+  (renamed from ``slave=`` in earlier 3.x releases).
+
+Exceptions
+----------
+``ModbusDriverError``
+    Base exception for all driver-level errors.
+``ModbusConnectionError``
+    Raised when the TCP connection to the gateway cannot be established or is
+    lost during the read.
+``ModbusResponseError``
+    Raised when the gateway responds with a Modbus exception frame or when the
+    returned register count does not match the requested count.
+"""
+
+from __future__ import annotations
+
+import logging
+import struct
+from typing import TYPE_CHECKING
+
+from pymodbus.client import ModbusTcpClient
+from pymodbus.exceptions import ConnectionException, ModbusException
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+logger = logging.getLogger(__name__)
+
+# ---------------------------------------------------------------------------
+# Custom exceptions
+# ---------------------------------------------------------------------------
+
+
+class ModbusDriverError(RuntimeError):
+    """Base class for all Modbus driver errors."""
+
+
+class ModbusConnectionError(ModbusDriverError):
+    """Cannot connect to (or lost connection with) the Modbus TCP gateway."""
+
+
+class ModbusResponseError(ModbusDriverError):
+    """Modbus gateway returned an exception frame or an unexpected response."""
+
+
+# ---------------------------------------------------------------------------
+# Block definition type alias
+# ---------------------------------------------------------------------------
+
+#: A single read block: ``{"start": int, "count": int}``.
+Block = dict[str, int]
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def read_blocks(
+    host: str,
+    port: int,
+    unit_id: int,
+    blocks: Sequence[Block],
+    *,
+    timeout: float = 3.0,
+) -> dict[int, int]:
+    """Read one or more contiguous register blocks via FC04 (input registers).
+
+    Parameters
+    ----------
+    host:
+        Hostname or IP address of the Modbus TCP gateway.
+    port:
+        TCP port (typically 502).
+    unit_id:
+        Modbus slave / unit address (the device's Meter ID for SDM120).
+    blocks:
+        Sequence of ``{"start": int, "count": int}`` dicts describing the
+        contiguous register ranges to read.  ``count`` is the number of
+        16-bit registers (not bytes).
+    timeout:
+        TCP connect/read timeout in seconds (default 3 s).
+
+    Returns
+    -------
+    dict[int, int]
+        Flat mapping of ``{register_address: 16-bit_register_value}`` for
+        every register returned across all blocks.
+
+    Raises
+    ------
+    ModbusConnectionError
+        If the TCP connection to the gateway fails.
+    ModbusResponseError
+        If the gateway returns a Modbus exception frame or an unexpected
+        number of registers.
+    """
+    client = ModbusTcpClient(host, port=port, timeout=timeout)
+    try:
+        connected = client.connect()
+        if not connected:
+            raise ModbusConnectionError(
+                f"Could not connect to Modbus gateway at {host}:{port}"
+            )
+
+        registers: dict[int, int] = {}
+        for block in blocks:
+            start: int = block["start"]
+            count: int = block["count"]
+            _read_block(client, unit_id, start, count, registers)
+
+        return registers
+
+    except ConnectionException as exc:
+        raise ModbusConnectionError(
+            f"Connection to Modbus gateway {host}:{port} failed: {exc}"
+        ) from exc
+    except ModbusException as exc:
+        raise ModbusResponseError(f"Modbus protocol error: {exc}") from exc
+    finally:
+        client.close()
+
+
+def _read_block(
+    client: ModbusTcpClient,
+    unit_id: int,
+    start: int,
+    count: int,
+    result: dict[int, int],
+) -> None:
+    """Read one block and merge into *result*.  Raises on any error."""
+    try:
+        response = client.read_input_registers(start, count=count, device_id=unit_id)
+    except ConnectionException as exc:
+        raise ModbusConnectionError(
+            f"Lost connection while reading registers 0x{start:04X}+{count}: {exc}"
+        ) from exc
+
+    if response.isError():
+        raise ModbusResponseError(
+            f"Modbus exception reading registers 0x{start:04X}+{count}: {response}"
+        )
+
+    regs = response.registers
+    if len(regs) != count:
+        raise ModbusResponseError(
+            f"Expected {count} registers from 0x{start:04X}, got {len(regs)}"
+        )
+
+    for offset, value in enumerate(regs):
+        result[start + offset] = value
+
+
+# ---------------------------------------------------------------------------
+# Decoding helpers
+# ---------------------------------------------------------------------------
+
+
+def registers_to_float(hi_reg: int, lo_reg: int) -> float:
+    """Decode two 16-bit registers to a big-endian IEEE-754 float32.
+
+    The SDM120 (and most Modbus float devices) use big-endian word order:
+    the high 16-bit register comes first, then the low register.  Combined
+    with big-endian byte order within each register, the raw 4-byte sequence
+    is standard network-byte-order (big-endian) float32.
+
+    Parameters
+    ----------
+    hi_reg:
+        The first (higher-address-range, most-significant) 16-bit register.
+    lo_reg:
+        The second (lower-address-range, least-significant) 16-bit register.
+
+    Returns
+    -------
+    float
+        The decoded IEEE-754 single-precision floating-point value.
+
+    Example
+    -------
+    >>> registers_to_float(0x4366, 0x3334)
+    230.20001220703125
+    """
+    raw = struct.pack(">HH", hi_reg, lo_reg)
+    return struct.unpack(">f", raw)[0]
@@ -0,0 +1,231 @@
+"""Modbus profile loader, validator, and decoder.
+
+A *profile* is a YAML file that describes the protocol-level knowledge for
+a particular Modbus device model:
+
+- Which registers to read (``blocks`` for efficient bulk reads).
+- How to decode each quantity (``metrics``: register address, type, unit, …).
+- Home Assistant metadata per metric (``device_class``, ``ha_component``, …).
+
+Profiles live in ``app/integrations/modbus/profiles/<name>.yaml`` and are
+located at runtime relative to *this file* (not CWD), so they work whether
+the package is installed as a wheel, run in-process, or invoked via
+``python -m scripts.modbus_cli``.
+
+Design notes
+------------
+- **Purely data + functions** — no abstract base classes or inheritance.
+- ``ModbusProfile`` and ``MetricSpec`` are Pydantic models: they validate on
+  construction and raise ``pydantic.ValidationError`` for malformed YAML.
+- ``decode`` uses ``driver.registers_to_float`` for float32 quantities.
+  Unsupported types are silently skipped with a warning (future-proofing for
+  int16/uint16 etc.).
+"""
+
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+from typing import Optional
+
+import yaml
+from pydantic import BaseModel, ValidationError
+
+from app.integrations.modbus.driver import registers_to_float
+
+logger = logging.getLogger(__name__)
+
+# Directory containing the YAML profiles, located relative to *this* file.
+_PROFILES_DIR = Path(__file__).parent / "profiles"
+
+
+# ---------------------------------------------------------------------------
+# Pydantic models for profile validation
+# ---------------------------------------------------------------------------
+
+
+class MetricSpec(BaseModel):
+    """Specification for a single measurable quantity within a profile."""
+
+    key: str
+    """Stable identifier used as the key in decoded payloads (e.g. ``"voltage"``)."""
+
+    address: int
+    """Starting Modbus register address (0-based, e.g. ``0x0000`` for voltage)."""
+
+    type: str
+    """Encoding type — currently only ``"float32"`` is supported."""
+
+    unit: str
+    """Physical unit string (e.g. ``"V"``, ``"A"``, ``"kWh"``).  Empty string for dimensionless."""
+
+    device_class: str
+    """Home Assistant device class (e.g. ``"voltage"``, ``"power"``, ``"energy"``)."""
+
+    ha_component: str
+    """Home Assistant component type (e.g. ``"sensor"``)."""
+
+    state_class: Optional[str] = None
+    """Home Assistant state class, if applicable (e.g. ``"total_increasing"``)."""
+
+
+class BlockSpec(BaseModel):
+    """A contiguous register block for bulk reading."""
+
+    start: int
+    """First register address in the block."""
+
+    count: int
+    """Number of 16-bit registers to read."""
+
+
+class ModbusProfile(BaseModel):
+    """Complete description of a Modbus device's protocol-level knowledge."""
+
+    name: str
+    """Short identifier matching the YAML file name (e.g. ``"sdm120"``)."""
+
+    description: str
+    """Human-readable description of the device."""
+
+    function_code: int
+    """Modbus function code for reading measurements (4 = FC04 input registers)."""
+
+    word_order: str
+    """Word (register) order: ``"big"`` means high register first."""
+
+    byte_order: str
+    """Byte order within each register: ``"big"`` means standard network order."""
+
+    blocks: list[BlockSpec]
+    """Register blocks to read in bulk, reducing Modbus transaction count."""
+
+    metrics: list[MetricSpec]
+    """List of individual measurable quantities and their decoding rules."""
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+class ProfileNotFoundError(FileNotFoundError):
+    """Raised when the requested profile YAML file does not exist."""
+
+
+class ProfileValidationError(ValueError):
+    """Raised when a profile YAML file fails Pydantic validation."""
+
+
+def load_profile(name: str) -> ModbusProfile:
+    """Load and validate a Modbus device profile by name.
+
+    The profile file is expected at
+    ``app/integrations/modbus/profiles/<name>.yaml``.
+
+    Parameters
+    ----------
+    name:
+        Profile name without extension (e.g. ``"sdm120"``).
+
+    Returns
+    -------
+    ModbusProfile
+        Validated profile model.
+
+    Raises
+    ------
+    ProfileNotFoundError
+        If ``profiles/<name>.yaml`` does not exist.
+    ProfileValidationError
+        If the YAML is syntactically valid but the content fails schema
+        validation (missing required fields, wrong types, etc.).
+    """
+    path = _PROFILES_DIR / f"{name}.yaml"
+    if not path.exists():
+        raise ProfileNotFoundError(
+            f"Modbus profile '{name}' not found (looked for {path})"
+        )
+
+    with path.open("r", encoding="utf-8") as fh:
+        raw = yaml.safe_load(fh)
+
+    try:
+        profile = ModbusProfile.model_validate(raw)
+    except ValidationError as exc:
+        raise ProfileValidationError(
+            f"Profile '{name}' failed validation: {exc}"
+        ) from exc
+
+    return profile
+
+
+def list_profiles() -> list[tuple[str, str]]:
+    """Return ``(name, description)`` pairs for all available profiles.
+
+    Scans ``app/integrations/modbus/profiles/*.yaml``, loads each, and
+    returns a sorted list of ``(name, description)`` tuples.  Profiles that
+    fail to load are skipped with a warning.
+    """
+    results: list[tuple[str, str]] = []
+    if not _PROFILES_DIR.exists():
+        return results
+
+    for path in sorted(_PROFILES_DIR.glob("*.yaml")):
+        name = path.stem
+        try:
+            profile = load_profile(name)
+            results.append((profile.name, profile.description))
+        except (ProfileNotFoundError, ProfileValidationError, Exception) as exc:
+            logger.warning("Skipping malformed profile '%s': %s", name, exc)
+
+    return results
+
+
+def decode(profile: ModbusProfile, registers: dict[int, int]) -> dict[str, float]:
+    """Decode raw register values into a mapping of ``{key: float_value}``.
+
+    For each metric in *profile*, the function looks up the two registers at
+    ``address`` and ``address + 1`` in *registers* and decodes them as a
+    big-endian float32 (high register first).
+
+    Metrics whose registers are absent from *registers* are skipped (not
+    an error — this can happen if a block was not requested or a device does
+    not populate that register).  Metrics with unsupported ``type`` values
+    are also skipped.
+
+    Parameters
+    ----------
+    profile:
+        Validated ``ModbusProfile`` describing the device.
+    registers:
+        Mapping of ``{register_address: 16-bit_value}`` as returned by
+        ``driver.read_blocks``.
+
+    Returns
+    -------
+    dict[str, float]
+        Decoded engineering values keyed by each metric's ``key`` field.
+    """
+    result: dict[str, float] = {}
+    for metric in profile.metrics:
+        if metric.type == "float32":
+            hi_addr = metric.address
+            lo_addr = metric.address + 1
+            if hi_addr not in registers or lo_addr not in registers:
+                logger.debug(
+                    "Skipping metric '%s': registers 0x%04X/0x%04X not available",
+                    metric.key,
+                    hi_addr,
+                    lo_addr,
+                )
+                continue
+            value = registers_to_float(registers[hi_addr], registers[lo_addr])
+            result[metric.key] = value
+        else:
+            logger.warning(
+                "Metric '%s' has unsupported type '%s', skipping",
+                metric.key,
+                metric.type,
+            )
+    return result
@@ -0,0 +1,74 @@
+name: sdm120
+description: Eastron SDM120 single-phase energy meter
+function_code: 4          # input registers (FC04)
+word_order: big           # high register first (big-endian word order)
+byte_order: big           # high byte first within each register
+
+blocks:
+  # Registers 30001–30095 (0x0000–0x005F): voltage through max export demand
+  - { start: 0x0000, count: 0x0060 }
+  # Registers 30343–30346 (0x0156–0x0159): total active/reactive energy
+  - { start: 0x0156, count: 0x0004 }
+
+metrics:
+  # Core measurements — addresses from SDM120 Modbus Protocol §4 (FC04 input registers)
+  # Each float32 occupies two consecutive 16-bit registers; address = Hex start in §4.
+
+  - key: voltage
+    address: 0x0000        # register 30001 — Voltage (V)
+    type: float32
+    unit: "V"
+    device_class: voltage
+    ha_component: sensor
+
+  - key: current
+    address: 0x0006        # register 30007 — Current (A)
+    type: float32
+    unit: "A"
+    device_class: current
+    ha_component: sensor
+
+  - key: active_power
+    address: 0x000C        # register 30013 — Active power (W)
+    type: float32
+    unit: "W"
+    device_class: power
+    ha_component: sensor
+
+  - key: power_factor
+    address: 0x001E        # register 30031 — Power factor (dimensionless)
+    type: float32
+    unit: ""
+    device_class: power_factor
+    ha_component: sensor
+
+  - key: frequency
+    address: 0x0046        # register 30071 — Frequency (Hz)
+    type: float32
+    unit: "Hz"
+    device_class: frequency
+    ha_component: sensor
+
+  - key: import_energy
+    address: 0x0048        # register 30073 — Import active energy (kWh)
+    type: float32
+    unit: "kWh"
+    device_class: energy
+    state_class: total_increasing
+    ha_component: sensor
+
+  - key: export_energy
+    address: 0x004A        # register 30075 — Export active energy (kWh)
+    type: float32
+    unit: "kWh"
+    device_class: energy
+    state_class: total_increasing
+    ha_component: sensor
+
+  - key: total_energy
+    address: 0x0156        # register 30343 — Total active energy (kWh)
+    type: float32
+    unit: "kWh"
+    device_class: energy
+    state_class: total_increasing
+    ha_component: sensor
@@ -0,0 +1,341 @@
+"""MQTT client integration (paho-mqtt 2.x).
+
+Provides :class:`MqttManager`: a long-lived MQTT client that runs paho's
+loop in a background thread.  Designed to be started in FastAPI's lifespan
+and shared across the application as a module-level singleton (``mqtt_manager``).
+
+Key design decisions
+--------------------
+- **paho 2.x API**: ``Client`` requires ``CallbackAPIVersion.VERSION2`` as the
+  first positional argument.  VERSION2 on_connect callback receives
+  ``(client, userdata, connect_flags, reason_code, properties)`` — not the
+  older RC int.
+- **Background thread**: ``loop_start()`` spawns a daemon thread; ``loop_stop()``
+  joins it cleanly on shutdown.
+- **Never crash the process**: all paho operations are wrapped in try/except;
+  connection failure is logged but does not propagate to the caller.
+- **Password safety**: the MQTT password is never passed to ``logger`` calls.
+- **Reconnect**: ``reconnect(settings)`` tears down the old client and
+  establishes a fresh connection with the new settings.  Callers (e.g. PUT
+  /api/config) call this after saving MQTT-related config values.
+- **Subscribe**: ``subscribe(topic, handler)`` registers a topic → handler
+  mapping.  Subscriptions are re-established automatically on reconnect.
+  The ``on_message`` callback dispatches incoming payloads to the registered
+  handler; handler exceptions are caught and logged so they never crash the
+  paho loop thread or the network connection.
+"""
+
+from __future__ import annotations
+
+import logging
+import threading
+from collections.abc import Callable
+from typing import TYPE_CHECKING
+
+import paho.mqtt.client as mqtt
+
+if TYPE_CHECKING:
+    from app.config import Settings
+
+logger = logging.getLogger(__name__)
+
+# MQTT settings keys that, when changed, should trigger a reconnect.
+MQTT_SETTINGS_KEYS = {
+    "mqtt_enabled",
+    "mqtt_broker_host",
+    "mqtt_broker_port",
+    "mqtt_username",
+    "mqtt_password",
+    "mqtt_tls_enabled",
+}
+
+
+def _is_configured(settings: Settings) -> bool:
+    """Return True if MQTT is enabled *and* the broker host is set."""
+    return bool(settings.mqtt_enabled and settings.mqtt_broker_host)
+
+
+class MqttManager:
+    """Long-lived MQTT client wrapper.
+
+    Lifecycle
+    ---------
+    1. ``connect(settings)`` — start background loop + connect to broker.
+    2. ``publish(...)`` — publish messages while connected.
+    3. ``disconnect()`` — graceful teardown (called on app shutdown).
+    4. ``reconnect(settings)`` — disconnect then re-connect with new settings
+       (called after saving updated MQTT configuration).
+
+    When MQTT is not enabled or not configured, all methods are no-ops.
+    Connection failures are caught and logged; they do not raise.
+    """
+
+    def __init__(self) -> None:
+        self._client: mqtt.Client | None = None
+        self._lock = threading.Lock()
+        self._connected = False
+        # topic → handler registry; persists across reconnects so subscriptions
+        # are automatically re-established when the client reconnects.
+        self._subscriptions: dict[str, Callable[[bytes], None]] = {}
+
+    # ------------------------------------------------------------------
+    # Public properties
+    # ------------------------------------------------------------------
+
+    @property
+    def is_connected(self) -> bool:
+        """True if the underlying paho client is currently connected."""
+        return self._connected
+
+    # ------------------------------------------------------------------
+    # Public interface
+    # ------------------------------------------------------------------
+
+    def is_configured(self, settings: Settings) -> bool:
+        """Return True if MQTT is enabled and broker host is configured."""
+        return _is_configured(settings)
+
+    def connect(self, settings: Settings) -> None:
+        """Connect to the MQTT broker and start the background loop thread.
+
+        No-op if MQTT is not enabled or broker host is not set.
+        Connection errors are logged but do not raise.
+        """
+        if not _is_configured(settings):
+            logger.debug("MQTT not configured or not enabled — skipping connect.")
+            return
+
+        with self._lock:
+            self._start_client(settings)
+
+    def disconnect(self) -> None:
+        """Disconnect from the broker and stop the background loop thread.
+
+        No-op if no client is active.
+        """
+        with self._lock:
+            self._stop_client()
+
+    def reconnect(self, settings: Settings) -> None:
+        """Disconnect the current client (if any) and reconnect with *settings*.
+
+        Call this after saving updated MQTT configuration values.
+        No-op if MQTT is not enabled or broker host is not set.
+        """
+        with self._lock:
+            self._stop_client()
+        self.connect(settings)
+
+    def publish(
+        self,
+        topic: str,
+        payload: str | bytes | None,
+        *,
+        retain: bool = False,
+        qos: int = 0,
+    ) -> None:
+        """Publish a message to *topic*.
+
+        If the client is not connected the call is silently skipped.
+        Errors are logged but do not raise.
+        """
+        with self._lock:
+            client = self._client
+
+        if client is None or not self._connected:
+            logger.debug("MQTT publish skipped — not connected (topic=%s).", topic)
+            return
+
+        try:
+            client.publish(topic, payload=payload, qos=qos, retain=retain)
+        except Exception:
+            logger.exception("MQTT publish error (topic=%s).", topic)
+
+    def subscribe(self, topic: str, handler: Callable[[bytes], None]) -> None:
+        """Register *handler* to be called when a message arrives on *topic*.
+
+        If the client is already connected, the subscription is sent to the
+        broker immediately.  Otherwise it is queued and will be established
+        the next time ``_on_connect`` fires (including after a reconnect).
+
+        Handler exceptions are swallowed by the ``on_message`` dispatcher so
+        that a buggy handler can never crash the paho loop thread.
+        """
+        self._subscriptions[topic] = handler
+        # Grab the client reference outside the lock to avoid holding the lock
+        # while calling back into paho (which may itself acquire internal locks).
+        with self._lock:
+            client = self._client
+            connected = self._connected
+
+        if client is not None and connected:
+            try:
+                client.subscribe(topic)
+                logger.debug("MQTT subscribed to topic=%s (immediate).", topic)
+            except Exception:
+                logger.exception("MQTT subscribe error (topic=%s).", topic)
+
+    def unsubscribe(self, topic: str) -> None:
+        """Remove the handler for *topic* and unsubscribe from the broker.
+
+        Idempotent: unknown topics are ignored.  Used to apply config changes
+        without a restart (e.g. when DSMR ingest is turned off or its topic
+        changes).  If the client is connected, the broker unsubscribe is sent
+        immediately; either way the handler is removed from the registry so it
+        will not be re-subscribed on the next ``_on_connect``.
+        """
+        self._subscriptions.pop(topic, None)
+        with self._lock:
+            client = self._client
+            connected = self._connected
+
+        if client is not None and connected:
+            try:
+                client.unsubscribe(topic)
+                logger.debug("MQTT unsubscribed from topic=%s.", topic)
+            except Exception:
+                logger.exception("MQTT unsubscribe error (topic=%s).", topic)
+
+    # ------------------------------------------------------------------
+    # Internal helpers — must be called with self._lock held
+    # ------------------------------------------------------------------
+
+    def _start_client(self, settings: Settings) -> None:
+        """Build a fresh paho Client, configure it, and call loop_start + connect."""
+        client = mqtt.Client(
+            callback_api_version=mqtt.CallbackAPIVersion.VERSION2,
+            client_id="home-automation",
+        )
+
+        # Callbacks — VERSION2 on_connect signature:
+        # (client, userdata, connect_flags, reason_code, properties)
+        def _on_connect(
+            _client: mqtt.Client,
+            _userdata: object,
+            _flags: mqtt.ConnectFlags,
+            reason_code: mqtt.ReasonCode,
+            _properties: mqtt.Properties | None,
+        ) -> None:
+            if reason_code.is_failure:
+                logger.warning("MQTT connection refused: %s", reason_code)
+                self._connected = False
+            else:
+                logger.info("MQTT connected (reason_code=%s).", reason_code)
+                self._connected = True
+                # Re-establish all registered subscriptions after (re-)connect.
+                for sub_topic in self._subscriptions:
+                    try:
+                        _client.subscribe(sub_topic)
+                        logger.debug("MQTT re-subscribed to topic=%s.", sub_topic)
+                    except Exception:
+                        logger.exception(
+                            "MQTT re-subscribe failed (topic=%s).", sub_topic
+                        )
+
+        # VERSION2 on_disconnect signature:
+        # (client, userdata, disconnect_flags, reason_code, properties)
+        def _on_disconnect(
+            _client: mqtt.Client,
+            _userdata: object,
+            _disconnect_flags: mqtt.DisconnectFlags,
+            reason_code: mqtt.ReasonCode,
+            _properties: mqtt.Properties | None,
+        ) -> None:
+            self._connected = False
+            if reason_code.is_failure:
+                logger.warning("MQTT disconnected unexpectedly (reason_code=%s).", reason_code)
+            else:
+                logger.info("MQTT disconnected cleanly.")
+
+        # VERSION2 on_message signature: (client, userdata, message)
+        def _on_message(
+            _client: mqtt.Client,
+            _userdata: object,
+            message: mqtt.MQTTMessage,
+        ) -> None:
+            handler = self._subscriptions.get(message.topic)
+            if handler is None:
+                logger.debug(
+                    "MQTT on_message: no handler for topic=%s.", message.topic
+                )
+                return
+            try:
+                handler(message.payload)
+            except Exception:
+                logger.exception(
+                    "MQTT message handler raised for topic=%s (swallowed).",
+                    message.topic,
+                )
+
+        client.on_connect = _on_connect
+        client.on_disconnect = _on_disconnect
+        client.on_message = _on_message
+
+        # TLS
+        if settings.mqtt_tls_enabled:
+            try:
+                client.tls_set()
+            except Exception:
+                logger.exception("MQTT TLS setup failed.")
+                return
+
+        # Credentials — never log the password
+        if settings.mqtt_username:
+            client.username_pw_set(
+                username=settings.mqtt_username,
+                password=settings.mqtt_password or None,
+            )
+
+        # Start background loop thread *before* connect so paho can handle
+        # the connection handshake asynchronously.
+        client.loop_start()
+
+        try:
+            client.connect(
+                host=settings.mqtt_broker_host,
+                port=settings.mqtt_broker_port,
+                keepalive=60,
+            )
+        except Exception:
+            # Log without leaking the password
+            logger.exception(
+                "MQTT connect failed (host=%s, port=%s). Stopping loop.",
+                settings.mqtt_broker_host,
+                settings.mqtt_broker_port,
+            )
+            try:
+                client.loop_stop()
+            except Exception:
+                pass
+            return
+
+        self._client = client
+        logger.info(
+            "MQTT client started (host=%s, port=%s).",
+            settings.mqtt_broker_host,
+            settings.mqtt_broker_port,
+        )
+
+    def _stop_client(self) -> None:
+        """Disconnect and stop the background loop.  Idempotent."""
+        client = self._client
+        if client is None:
+            return
+        self._client = None
+        self._connected = False
+        try:
+            client.disconnect()
+        except Exception:
+            logger.debug("MQTT disconnect raised (ignoring).", exc_info=True)
+        try:
+            client.loop_stop()
+        except Exception:
+            logger.debug("MQTT loop_stop raised (ignoring).", exc_info=True)
+        logger.info("MQTT client stopped.")
+
+
+# ---------------------------------------------------------------------------
+# Module-level singleton — shared across lifespan and route handlers
+# ---------------------------------------------------------------------------
+
+mqtt_manager = MqttManager()
@@ -0,0 +1,11 @@
+"""Pricing profile framework and strategy registry.
+
+This package provides:
+
+- ``profiles``: Pydantic models describing the structure of pricing profiles
+  (``ManualProfile`` / ``TibberProfile``), YAML loaders, and contract-values
+  validation (``load_profile`` / ``list_profiles`` / ``validate_values``).
+- ``strategies``: A lightweight registry of price-calculation strategies
+  (``register_strategy`` / ``get_strategy``), with built-in implementations for
+  the ``manual`` (fixed dual-tariff) and ``tibber`` (dynamic API) kinds.
+"""
@@ -0,0 +1,393 @@
+"""Pricing profile loader, validator, and contract-values checker.
+
+A *pricing profile* is a YAML file that describes the **structure** of an energy
+contract — which fields exist, their units, and which have defaults.  Actual
+pricing values (the numbers the user fills in via the UI) are stored in the DB
+as ``EnergyContractVersion.values`` (a JSON blob) and must conform to the
+corresponding profile's structure.
+
+Profiles live in ``app/integrations/pricing/profiles/<kind>.yaml`` and are
+located at runtime relative to *this file* (not CWD), matching the pattern
+established by the Modbus profile loader.
+
+Design notes
+------------
+- **Purely data + functions** — no abstract base classes or inheritance.
+- Two Pydantic models — ``ManualProfile`` and ``TibberProfile`` — capture the
+  different structures of the two supported kinds.  A thin union dispatcher in
+  ``load_profile`` picks the right one.
+- ``validate_values(kind, values)`` fills in fields that carry a ``default`` and
+  raises ``ProfileValidationError`` for missing required fields or wrong types.
+- All errors are subclasses of built-ins so callers need not import this module
+  just to catch them.
+"""
+
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+from typing import Any, Optional
+
+import yaml
+from pydantic import BaseModel, ValidationError, model_validator
+
+logger = logging.getLogger(__name__)
+
+# Directory containing the YAML profiles, located relative to *this* file.
+_PROFILES_DIR = Path(__file__).parent / "profiles"
+
+
+# ---------------------------------------------------------------------------
+# Custom exceptions
+# ---------------------------------------------------------------------------
+
+
+class ProfileNotFoundError(FileNotFoundError):
+    """Raised when the requested profile YAML file does not exist."""
+
+
+class ProfileValidationError(ValueError):
+    """Raised when a profile YAML fails Pydantic validation or when contract
+    values do not conform to the profile structure."""
+
+
+# ---------------------------------------------------------------------------
+# Leaf-node models (a single pricing field: unit + optional default)
+# ---------------------------------------------------------------------------
+
+
+class FieldSpec(BaseModel):
+    """Specification for a single numeric pricing field."""
+
+    unit: str
+    """Physical / monetary unit string (e.g. ``"EUR/kWh"``, ``"EUR/month"``)."""
+
+    default: Optional[float] = None
+    """Default value used when the field is absent from contract values.
+    ``None`` means the field is required (no default)."""
+
+
+# ---------------------------------------------------------------------------
+# ManualProfile — fixed / variable dual-tariff contract structure
+# ---------------------------------------------------------------------------
+
+
+class ManualBuySpec(BaseModel):
+    normal: FieldSpec  # high-tariff buy price (delivered_2 registers)
+    dal: FieldSpec  # low-tariff buy price (delivered_1 registers)
+
+
+class ManualSellSpec(BaseModel):
+    normal: FieldSpec  # high-tariff sell / return price
+    dal: FieldSpec  # low-tariff sell / return price
+
+
+class ManualEnergySpec(BaseModel):
+    dual_tariff: bool  # always True for manual profiles
+    buy: ManualBuySpec
+    sell: ManualSellSpec
+    energy_tax: FieldSpec  # added to buy price; includes VAT
+    ode: FieldSpec  # currently merged into energy_tax; default 0
+
+
+class ManualStandingSpec(BaseModel):
+    network_fee: FieldSpec  # EUR/month
+    management_fee: FieldSpec  # EUR/month
+
+
+class ManualCreditsSpec(BaseModel):
+    heffingskorting: FieldSpec  # EUR/year — energy-tax credit deducted at summary
+
+
+class ManualProfile(BaseModel):
+    """Complete structure description for a ``manual`` pricing contract."""
+
+    kind: str
+    label: str
+    energy: ManualEnergySpec
+    standing: ManualStandingSpec
+    credits: ManualCreditsSpec
+
+    @model_validator(mode="after")
+    def _check_kind(self) -> "ManualProfile":
+        if self.kind != "manual":
+            raise ValueError(f"ManualProfile requires kind='manual', got {self.kind!r}")
+        return self
+
+
+# ---------------------------------------------------------------------------
+# TibberProfile — dynamic Tibber API contract structure
+# ---------------------------------------------------------------------------
+
+
+class TibberEnergySpec(BaseModel):
+    source: str  # must be "tibber_api"
+    energy_tax: FieldSpec  # subtracted from total to derive sell price
+    sell_adjust: FieldSpec  # additional sell-price adjustment; default 0
+
+
+class TibberStandingSpec(BaseModel):
+    management_fee: FieldSpec  # EUR/month; has a default
+    network_fee: FieldSpec  # EUR/month
+
+
+class TibberCreditsSpec(BaseModel):
+    heffingskorting: FieldSpec  # EUR/year
+
+
+class TibberProfile(BaseModel):
+    """Complete structure description for a ``tibber`` pricing contract."""
+
+    kind: str
+    label: str
+    energy: TibberEnergySpec
+    standing: TibberStandingSpec
+    credits: TibberCreditsSpec
+
+    @model_validator(mode="after")
+    def _check_kind(self) -> "TibberProfile":
+        if self.kind != "tibber":
+            raise ValueError(f"TibberProfile requires kind='tibber', got {self.kind!r}")
+        return self
+
+
+# A union type for type hints where either profile is acceptable.
+AnyProfile = ManualProfile | TibberProfile
+
+# Map kind → Pydantic model class used for validation.
+_PROFILE_MODELS: dict[str, type[ManualProfile] | type[TibberProfile]] = {
+    "manual": ManualProfile,
+    "tibber": TibberProfile,
+}
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def load_profile(kind: str) -> AnyProfile:
+    """Load and validate a pricing profile by kind name.
+
+    The profile file is expected at
+    ``app/integrations/pricing/profiles/<kind>.yaml``.
+
+    Parameters
+    ----------
+    kind:
+        Profile kind without extension (``"manual"`` or ``"tibber"``).
+
+    Returns
+    -------
+    ManualProfile | TibberProfile
+        Validated profile model.
+
+    Raises
+    ------
+    ProfileNotFoundError
+        If ``profiles/<kind>.yaml`` does not exist.
+    ProfileValidationError
+        If the YAML is syntactically valid but fails schema validation.
+    """
+    path = _PROFILES_DIR / f"{kind}.yaml"
+    if not path.exists():
+        raise ProfileNotFoundError(
+            f"Pricing profile '{kind}' not found (looked for {path})"
+        )
+
+    with path.open("r", encoding="utf-8") as fh:
+        raw = yaml.safe_load(fh)
+
+    if not isinstance(raw, dict):
+        raise ProfileValidationError(
+            f"Profile '{kind}': expected a YAML mapping, got {type(raw).__name__}"
+        )
+
+    # Choose the right Pydantic model based on the ``kind`` field in the YAML.
+    yaml_kind = raw.get("kind", kind)
+    model_cls = _PROFILE_MODELS.get(yaml_kind)
+    if model_cls is None:
+        raise ProfileValidationError(
+            f"Profile '{kind}' has unknown kind={yaml_kind!r}; "
+            f"supported: {list(_PROFILE_MODELS)}"
+        )
+
+    try:
+        return model_cls.model_validate(raw)
+    except ValidationError as exc:
+        raise ProfileValidationError(
+            f"Profile '{kind}' failed validation: {exc}"
+        ) from exc
+
+
+def list_profiles() -> list[dict[str, Any]]:
+    """Return structural data for all available pricing profiles.
+
+    Scans ``app/integrations/pricing/profiles/*.yaml``, loads each, and returns
+    a list of dicts (Pydantic model dumps).  Profiles that fail to load are
+    skipped with a warning.
+
+    Returns
+    -------
+    list[dict[str, Any]]
+        One entry per valid profile, suitable for JSON serialisation and
+        front-end form rendering.
+    """
+    results: list[dict[str, Any]] = []
+    if not _PROFILES_DIR.exists():
+        return results
+
+    for path in sorted(_PROFILES_DIR.glob("*.yaml")):
+        kind = path.stem
+        try:
+            profile = load_profile(kind)
+            results.append(profile.model_dump())
+        except (ProfileNotFoundError, ProfileValidationError, Exception) as exc:
+            logger.warning("Skipping malformed pricing profile '%s': %s", kind, exc)
+
+    return results
+
+
+# ---------------------------------------------------------------------------
+# Contract-values validation
+# ---------------------------------------------------------------------------
+
+
+def _fill_defaults_manual(values: dict[str, Any], profile: ManualProfile) -> dict[str, Any]:
+    """Return a copy of *values* with any ``ode`` default applied if missing."""
+    filled = dict(values)
+
+    energy = dict(filled.get("energy", {}))
+
+    # Apply default for ode (default=0) if absent.
+    if "ode" not in energy and profile.energy.ode.default is not None:
+        energy["ode"] = profile.energy.ode.default
+
+    filled["energy"] = energy
+    return filled
+
+
+def _fill_defaults_tibber(values: dict[str, Any], profile: TibberProfile) -> dict[str, Any]:
+    """Return a copy of *values* with sell_adjust and management_fee defaults applied."""
+    filled = dict(values)
+
+    energy = dict(filled.get("energy", {}))
+    # Apply default for sell_adjust (default=0) if absent.
+    if "sell_adjust" not in energy and profile.energy.sell_adjust.default is not None:
+        energy["sell_adjust"] = profile.energy.sell_adjust.default
+    filled["energy"] = energy
+
+    standing = dict(filled.get("standing", {}))
+    # Apply default for management_fee if absent.
+    if (
+        "management_fee" not in standing
+        and profile.standing.management_fee.default is not None
+    ):
+        standing["management_fee"] = profile.standing.management_fee.default
+    filled["standing"] = standing
+
+    return filled
+
+
+def _require_numeric(section: str, key: str, container: dict[str, Any]) -> None:
+    """Assert that *container[key]* exists and is a number; raise ProfileValidationError."""
+    if key not in container:
+        raise ProfileValidationError(
+            f"Contract values missing required field '{section}.{key}'"
+        )
+    val = container[key]
+    if not isinstance(val, (int, float)):
+        raise ProfileValidationError(
+            f"Contract values field '{section}.{key}' must be a number, "
+            f"got {type(val).__name__!r}"
+        )
+
+
+def _validate_manual_values(values: dict[str, Any], profile: ManualProfile) -> dict[str, Any]:
+    """Validate and fill-defaults for manual contract values.
+
+    Returns the filled values dict on success.  Raises ProfileValidationError
+    on missing required fields or wrong types.
+    """
+    filled = _fill_defaults_manual(values, profile)
+    energy = filled.get("energy", {})
+    buy = energy.get("buy", {})
+    sell = energy.get("sell", {})
+    standing = filled.get("standing", {})
+    credits = filled.get("credits", {})
+
+    # Required energy.buy fields.
+    _require_numeric("energy.buy", "normal", buy)
+    _require_numeric("energy.buy", "dal", buy)
+    # Required energy.sell fields.
+    _require_numeric("energy.sell", "normal", sell)
+    _require_numeric("energy.sell", "dal", sell)
+    # Required energy fields.
+    _require_numeric("energy", "energy_tax", energy)
+    _require_numeric("energy", "ode", energy)
+    # Required standing fields.
+    _require_numeric("standing", "network_fee", standing)
+    _require_numeric("standing", "management_fee", standing)
+    # Required credits fields.
+    _require_numeric("credits", "heffingskorting", credits)
+
+    return filled
+
+
+def _validate_tibber_values(values: dict[str, Any], profile: TibberProfile) -> dict[str, Any]:
+    """Validate and fill-defaults for tibber contract values.
+
+    Returns the filled values dict on success.  Raises ProfileValidationError
+    on missing required fields or wrong types.
+    """
+    filled = _fill_defaults_tibber(values, profile)
+    energy = filled.get("energy", {})
+    standing = filled.get("standing", {})
+    credits = filled.get("credits", {})
+
+    # Required energy fields.
+    _require_numeric("energy", "energy_tax", energy)
+    _require_numeric("energy", "sell_adjust", energy)
+    # Required standing fields.
+    _require_numeric("standing", "management_fee", standing)
+    _require_numeric("standing", "network_fee", standing)
+    # Required credits fields.
+    _require_numeric("credits", "heffingskorting", credits)
+
+    return filled
+
+
+def validate_values(kind: str, values: dict[str, Any]) -> dict[str, Any]:
+    """Validate a contract-values dict against the named profile structure.
+
+    Fields that carry a ``default`` in the profile (e.g. ``ode``,
+    ``sell_adjust``, tibber ``management_fee``) are silently filled in when
+    absent from *values*.  Fields with no default that are absent, or fields
+    whose value is not a number, cause a ``ProfileValidationError``.
+
+    Parameters
+    ----------
+    kind:
+        Profile kind (``"manual"`` or ``"tibber"``).
+    values:
+        Contract values dict as stored in ``EnergyContractVersion.values``.
+
+    Returns
+    -------
+    dict[str, Any]
+        A (possibly mutated) copy of *values* with defaults applied.
+
+    Raises
+    ------
+    ProfileNotFoundError
+        If the profile YAML for *kind* does not exist.
+    ProfileValidationError
+        If required fields are missing or have wrong types.
+    """
+    profile = load_profile(kind)
+    if isinstance(profile, ManualProfile):
+        return _validate_manual_values(values, profile)
+    if isinstance(profile, TibberProfile):
+        return _validate_tibber_values(values, profile)
+    # Unreachable with current kinds, but guard for future extensions.
+    raise ProfileValidationError(f"No validator implemented for kind={kind!r}")
@@ -0,0 +1,20 @@
+kind: manual
+label: 固定 / 可变费率（NL，双费率）
+
+energy:
+  dual_tariff: true              # use delivered_1/2, returned_1/2 for low/high tariffs
+  buy:
+    normal: { unit: EUR/kWh }   # high-tariff buy price (delivered_2 register)
+    dal:    { unit: EUR/kWh }   # low-tariff buy price (delivered_1 register)
+  sell:
+    normal: { unit: EUR/kWh }   # high-tariff sell / return price
+    dal:    { unit: EUR/kWh }   # low-tariff sell / return price (currently equal to normal)
+  energy_tax: { unit: EUR/kWh } # energy tax added to buy price (incl. VAT)
+  ode:        { unit: EUR/kWh, default: 0 }  # currently merged into energy_tax
+
+standing:                        # fixed charges; UI fills per month, engine prorates to days
+  network_fee:    { unit: EUR/month }
+  management_fee: { unit: EUR/month }
+
+credits:
+  heffingskorting: { unit: EUR/year }  # energy-tax credit; deducted at summary layer
@@ -0,0 +1,14 @@
+kind: tibber
+label: Tibber 动态电价（15 分钟）
+
+energy:
+  source: tibber_api              # buy = total (from API); sell = total − energy_tax − sell_adjust
+  energy_tax:  { unit: EUR/kWh }  # subtracted from total to derive sell price (incl. VAT)
+  sell_adjust: { unit: EUR/kWh, default: 0 }  # additional sell-price adjustment (residual spread)
+
+standing:                         # fixed charges; UI fills per month, engine prorates to days
+  management_fee: { unit: EUR/month, default: 5.99 }
+  network_fee:    { unit: EUR/month }
+
+credits:
+  heffingskorting: { unit: EUR/year }  # energy-tax credit; deducted at summary layer
@@ -0,0 +1,288 @@
+"""Price-calculation strategy registry and built-in implementations.
+
+A *strategy* is a plain function registered under a ``kind`` string.  Given
+per-register kWh deltas, the period start time, the active contract-version
+values, and a DB session, it returns a result dict with:
+
+    {
+        "import_cost":    Decimal,   # total cost of electricity drawn from grid
+        "export_revenue": Decimal,   # total revenue from electricity fed to grid
+        "net_cost":       Decimal,   # import_cost − export_revenue
+        "pricing":        dict,      # snapshot of the price inputs used (for auditing)
+    }
+
+**Import and export are kept separate throughout** — net_cost is only derived
+at the end.  This supports the Dutch no-netting rule (saldering afgebouwd).
+
+**All monetary arithmetic uses Decimal** converted via ``Decimal(str(x))`` to
+avoid float binary rounding errors.
+
+Design notes
+------------
+- **Purely data + functions**: no ABC, no class hierarchy.  A ``dict``-based
+  registry is the simplest structure that supports the two current kinds and
+  leaves the door open for future additions (e.g. ``octopus``, ``frank``).
+- ``deltas`` is a plain dataclass ``PeriodDeltas`` — typed, but no ORM.
+- Tibber strategy queries ``TibberPrice`` directly from the session; it does not
+  call the Tibber API (that is T05's job).
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from datetime import datetime
+from decimal import Decimal
+from typing import Any, Callable
+
+from sqlalchemy.orm import Session
+
+logger = logging.getLogger(__name__)
+
+
+# ---------------------------------------------------------------------------
+# Shared data types
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class PeriodDeltas:
+    """Per-register kWh deltas for one 15-minute billing period.
+
+    All values are ``Decimal`` and represent ``end_reading − start_reading``
+    for the corresponding cumulative energy register.
+
+    Attributes
+    ----------
+    d1: Decimal
+        Delivered (consumed) kWh on the low/dal tariff register (delivered_1).
+    d2: Decimal
+        Delivered (consumed) kWh on the normal/high tariff register (delivered_2).
+    r1: Decimal
+        Returned (fed-to-grid) kWh on the low/dal tariff register (returned_1).
+    r2: Decimal
+        Returned (fed-to-grid) kWh on the normal/high tariff register (returned_2).
+    """
+
+    d1: Decimal  # delivered low-tariff
+    d2: Decimal  # delivered high-tariff
+    r1: Decimal  # returned low-tariff
+    r2: Decimal  # returned high-tariff
+
+
+# Strategy callable signature.
+StrategyFn = Callable[
+    [PeriodDeltas, datetime, dict[str, Any], Session],
+    dict[str, Any],
+]
+
+
+# ---------------------------------------------------------------------------
+# Registry
+# ---------------------------------------------------------------------------
+
+_REGISTRY: dict[str, StrategyFn] = {}
+
+
+def register_strategy(kind: str, fn: StrategyFn) -> None:
+    """Register *fn* as the price-calculation strategy for *kind*.
+
+    Overwrites any previously registered strategy for the same kind (allows
+    monkey-patching in tests).
+    """
+    _REGISTRY[kind] = fn
+
+
+def get_strategy(kind: str) -> StrategyFn:
+    """Return the registered strategy for *kind*.
+
+    Raises
+    ------
+    KeyError
+        If no strategy is registered for *kind*.
+    """
+    if kind not in _REGISTRY:
+        raise KeyError(
+            f"No price strategy registered for kind={kind!r}. "
+            f"Available: {sorted(_REGISTRY)}"
+        )
+    return _REGISTRY[kind]
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _to_decimal(value: Any) -> Decimal:
+    """Convert *value* to Decimal via str() to avoid float binary rounding."""
+    return Decimal(str(value))
+
+
+# ---------------------------------------------------------------------------
+# Manual strategy — fixed dual-tariff
+# ---------------------------------------------------------------------------
+
+
+def _manual_strategy(
+    deltas: PeriodDeltas,
+    t0: datetime,
+    values: dict[str, Any],
+    session: Session,
+) -> dict[str, Any]:
+    """Calculate billing costs for one period using fixed dual-tariff rates.
+
+    Formula (§3.4):
+    - ``buy_dal    = energy.buy.dal    + energy.energy_tax + energy.ode``
+    - ``buy_normal = energy.buy.normal + energy.energy_tax + energy.ode``
+    - ``import_cost   = Δd1 × buy_dal + Δd2 × buy_normal``
+    - ``sell_dal    = energy.sell.dal``    (no tax on return price)
+    - ``sell_normal = energy.sell.normal``
+    - ``export_revenue = Δr1 × sell_dal + Δr2 × sell_normal``
+    - ``net_cost = import_cost − export_revenue``
+
+    The ``pricing`` snapshot contains all per-unit prices used so that the
+    result is fully auditable without re-querying the contract version.
+    """
+    energy = values.get("energy", {})
+    buy = energy.get("buy", {})
+    sell = energy.get("sell", {})
+
+    energy_tax = _to_decimal(energy.get("energy_tax", 0))
+    ode = _to_decimal(energy.get("ode", 0))
+
+    buy_dal_base = _to_decimal(buy.get("dal", 0))
+    buy_normal_base = _to_decimal(buy.get("normal", 0))
+    sell_dal = _to_decimal(sell.get("dal", 0))
+    sell_normal = _to_decimal(sell.get("normal", 0))
+
+    # Effective buy prices including all taxes.
+    buy_dal = buy_dal_base + energy_tax + ode
+    buy_normal = buy_normal_base + energy_tax + ode
+
+    import_cost = deltas.d1 * buy_dal + deltas.d2 * buy_normal
+    export_revenue = deltas.r1 * sell_dal + deltas.r2 * sell_normal
+    net_cost = import_cost - export_revenue
+
+    pricing_snapshot = {
+        "kind": "manual",
+        "buy_dal": str(buy_dal),
+        "buy_normal": str(buy_normal),
+        "sell_dal": str(sell_dal),
+        "sell_normal": str(sell_normal),
+        "energy_tax": str(energy_tax),
+        "ode": str(ode),
+    }
+
+    return {
+        "import_cost": import_cost,
+        "export_revenue": export_revenue,
+        "net_cost": net_cost,
+        "pricing": pricing_snapshot,
+    }
+
+
+# ---------------------------------------------------------------------------
+# Tibber strategy — dynamic 15-minute spot price
+# ---------------------------------------------------------------------------
+
+
+class TibberPriceNotFoundError(LookupError):
+    """Raised when no TibberPrice row covers the requested period start.
+
+    The billing engine (T07) catches this to mark the period as ``degraded``
+    or skip it until a price becomes available.
+    """
+
+
+def _tibber_strategy(
+    deltas: PeriodDeltas,
+    t0: datetime,
+    values: dict[str, Any],
+    session: Session,
+) -> dict[str, Any]:
+    """Calculate billing costs for one period using Tibber dynamic pricing.
+
+    Price lookup:
+        Takes the most recent ``TibberPrice`` row where ``starts_at ≤ t0``
+        (i.e. the slot that was in effect at *t0*).  This is a DESC LIMIT 1
+        query on ``starts_at``.
+
+    Formula (§3.4):
+    - ``buy  = total`` (Tibber's all-inclusive price, already includes tax)
+    - ``sell = total − energy_tax − sell_adjust``
+    - ``import_cost   = (Δd1 + Δd2) × buy``
+    - ``export_revenue = (Δr1 + Δr2) × sell``
+    - ``net_cost = import_cost − export_revenue``
+
+    Tibber does not differentiate tariff slots (dal vs normal) — the 15-minute
+    API price applies to the full delivered/returned volume.
+
+    Negative ``total`` (extreme negative spot prices):
+        When ``total`` is negative the ``sell`` price will also be negative,
+        meaning ``export_revenue`` becomes negative (feeding to grid *costs*
+        money).  This is the mathematically correct outcome and is left as-is.
+
+    Raises
+    ------
+    TibberPriceNotFoundError
+        If no ``TibberPrice`` row exists with ``starts_at ≤ t0``.  The caller
+        (T07 billing engine) should catch this and mark the period as
+        ``degraded`` or skip it for later recomputation.
+    """
+    from app.models.energy import TibberPrice  # local import to avoid circular
+    from sqlalchemy import desc
+
+    price_row: TibberPrice | None = (
+        session.query(TibberPrice)
+        .filter(TibberPrice.starts_at <= t0)
+        .order_by(desc(TibberPrice.starts_at))
+        .first()
+    )
+
+    if price_row is None:
+        raise TibberPriceNotFoundError(
+            f"No TibberPrice found covering t0={t0.isoformat()!r}; "
+            "period cannot be billed until price data is available."
+        )
+
+    energy = values.get("energy", {})
+    energy_tax = _to_decimal(energy.get("energy_tax", 0))
+    sell_adjust = _to_decimal(energy.get("sell_adjust", 0))
+
+    total = _to_decimal(price_row.total)
+    buy = total
+    sell = total - energy_tax - sell_adjust
+
+    total_delivered = deltas.d1 + deltas.d2
+    total_returned = deltas.r1 + deltas.r2
+
+    import_cost = total_delivered * buy
+    export_revenue = total_returned * sell
+    net_cost = import_cost - export_revenue
+
+    pricing_snapshot = {
+        "kind": "tibber",
+        "tibber_price_starts_at": price_row.starts_at.isoformat(),
+        "tibber_price_id": price_row.id,
+        "total": str(total),
+        "buy": str(buy),
+        "sell": str(sell),
+        "energy_tax": str(energy_tax),
+        "sell_adjust": str(sell_adjust),
+    }
+
+    return {
+        "import_cost": import_cost,
+        "export_revenue": export_revenue,
+        "net_cost": net_cost,
+        "pricing": pricing_snapshot,
+    }
+
+
+# ---------------------------------------------------------------------------
+# Register built-in strategies at module import time
+# ---------------------------------------------------------------------------
+
+register_strategy("manual", _manual_strategy)
+register_strategy("tibber", _tibber_strategy)
@@ -0,0 +1,10 @@
+"""Tibber dynamic electricity pricing integration.
+
+This package provides:
+  - ``client``: HTTP client for the Tibber GraphQL API (price fetching).
+  - Custom exceptions: ``TibberError`` (base) and ``TibberAuthError`` (auth failure).
+
+Usage::
+
+    from app.integrations.tibber.client import fetch_price_range, TibberAuthError
+"""
@@ -0,0 +1,329 @@
+"""Tibber GraphQL API client for fetching electricity price data.
+
+Design decisions
+----------------
+- Uses ``httpx`` (already a project dependency) for all HTTP requests.
+- Token is **never** written to log messages or exception strings to prevent
+  credential leakage into log aggregators.
+- ``fetch_price_range`` returns a list of ``PricePoint`` objects with UTC-aware
+  ``starts_at`` datetimes; the number of nodes is not assumed — all returned
+  nodes are parsed regardless of count.
+- ``fetch_current_price`` uses a separate, simpler query that asks for the
+  *current* price point only; used by the connection-test endpoint (T09) to
+  produce a fast three-state result (success / auth-error / network-error).
+- Authentication failures (HTTP 401/403) are raised as ``TibberAuthError`` so
+  that callers (the test endpoint) can distinguish them from generic network or
+  API errors.
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from typing import Any
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+_TIBBER_API_URL = "https://api.tibber.com/v1-beta/gql"
+_DEFAULT_TIMEOUT = 15.0
+
+# GraphQL query to fetch a range of 15-minute price nodes.
+# ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` fetches up to
+# 96 quarter-hourly slots which covers today + tomorrow (2 × 24 × 4 = 192 max,
+# but the Tibber API typically starts from the current slot and returns at
+# most the remaining hours of today plus tomorrow, so 96 is a good cap for
+# "today + tomorrow").
+_PRICE_RANGE_QUERY = """
+{
+  viewer {
+    homes {
+      id
+      currentSubscription {
+        priceInfoRange(resolution: QUARTER_HOURLY, first: 96) {
+          nodes {
+            startsAt
+            total
+            energy
+            tax
+            currency
+            level
+          }
+        }
+      }
+    }
+  }
+}
+"""
+
+# GraphQL query to fetch the single *current* price point.
+_CURRENT_PRICE_QUERY = """
+{
+  viewer {
+    homes {
+      id
+      currentSubscription {
+        priceInfo {
+          current {
+            startsAt
+            total
+            energy
+            tax
+            currency
+            level
+          }
+        }
+      }
+    }
+  }
+}
+"""
+
+
+# ---------------------------------------------------------------------------
+# Custom exceptions
+# ---------------------------------------------------------------------------
+
+
+class TibberError(Exception):
+    """Base class for all Tibber client errors.
+
+    Raised for network failures, timeouts, unexpected HTTP status codes, and
+    malformed API responses.  The exception message will **never** contain the
+    API token.
+    """
+
+
+class TibberAuthError(TibberError):
+    """Raised when the Tibber API rejects the provided token (HTTP 401/403).
+
+    Callers that implement a three-state connection test should catch this
+    exception separately from ``TibberError`` to distinguish auth problems
+    from network / API problems.
+    """
+
+
+# ---------------------------------------------------------------------------
+# Data model
+# ---------------------------------------------------------------------------
+
+
+@dataclass(slots=True)
+class PricePoint:
+    """One 15-minute price slot returned by the Tibber API.
+
+    All monetary values are in ``currency`` and include VAT (user-facing).
+    ``starts_at`` is always a timezone-aware UTC datetime regardless of the
+    timezone offset that Tibber returns in ``startsAt``.
+    """
+
+    starts_at: datetime  # UTC-aware
+    total: float         # full all-in price (energy + tax)
+    energy: float        # spot energy component
+    tax: float           # tax component
+    currency: str        # ISO 4217 (typically "EUR")
+    level: str | None    # e.g. "CHEAP", "NORMAL", "EXPENSIVE"; None if absent
+    resolution: str      # label for the slot resolution (e.g. "QUARTER_HOURLY")
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _parse_starts_at(raw: str) -> datetime:
+    """Parse an ISO 8601 timestamp with timezone offset and convert to UTC.
+
+    Tibber returns timestamps like ``2026-06-23T00:00:00.000+02:00``.
+    ``datetime.fromisoformat`` handles this format in Python 3.11+; the result
+    is then converted to UTC via ``.astimezone(UTC)``.
+    """
+    return datetime.fromisoformat(raw).astimezone(UTC)
+
+
+def _parse_node(node: dict[str, Any], resolution: str) -> PricePoint:
+    """Parse a single price node dict into a ``PricePoint``."""
+    return PricePoint(
+        starts_at=_parse_starts_at(node["startsAt"]),
+        total=float(node["total"]),
+        energy=float(node["energy"]),
+        tax=float(node["tax"]),
+        currency=str(node["currency"]),
+        level=node.get("level") or None,
+        resolution=resolution,
+    )
+
+
+def _pick_home(homes: list[dict[str, Any]], home_id: str | None) -> dict[str, Any]:
+    """Return the home dict matching *home_id*, or the first home if None."""
+    if not homes:
+        raise TibberError("Tibber API returned no homes")
+    if home_id is not None:
+        for h in homes:
+            if h.get("id") == home_id:
+                return h
+        raise TibberError("Tibber home id not found in API response")
+    return homes[0]
+
+
+def _post_graphql(token: str, query: str, timeout: float) -> dict[str, Any]:
+    """POST the GraphQL *query* and return the parsed ``data`` dict.
+
+    Raises
+    ------
+    TibberAuthError
+        On HTTP 401 or 403.
+    TibberError
+        On timeouts, network errors, non-2xx responses, or unexpected body shape.
+    """
+    headers = {
+        "Authorization": f"Bearer {token}",
+        "Content-Type": "application/json",
+    }
+    try:
+        response = httpx.post(
+            _TIBBER_API_URL,
+            json={"query": query},
+            headers=headers,
+            timeout=timeout,
+        )
+    except httpx.TimeoutException as exc:
+        raise TibberError("Tibber API request timed out") from exc
+    except httpx.HTTPError as exc:
+        raise TibberError("Tibber API request failed") from exc
+
+    if response.status_code in (401, 403):
+        raise TibberAuthError("Tibber API authentication failed")
+
+    try:
+        response.raise_for_status()
+    except httpx.HTTPStatusError as exc:
+        raise TibberError(f"Tibber API returned unexpected status {response.status_code}") from exc
+
+    try:
+        body = response.json()
+    except Exception as exc:
+        raise TibberError("Tibber API returned non-JSON response") from exc
+
+    if "errors" in body:
+        # GraphQL errors are not HTTP errors; surface them as TibberError.
+        # Do not include token in the message.
+        raise TibberError("Tibber GraphQL returned errors")
+
+    data = body.get("data")
+    if data is None:
+        raise TibberError("Tibber API response missing 'data' field")
+
+    return data
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def fetch_price_range(
+    token: str,
+    home_id: str | None = None,
+    *,
+    timeout: float = _DEFAULT_TIMEOUT,
+) -> list[PricePoint]:
+    """Fetch a range of 15-minute price nodes from the Tibber API.
+
+    Sends the ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` query
+    and parses every returned node into a ``PricePoint``.  The number of nodes
+    is not assumed — all returned nodes are parsed regardless of count.
+
+    Parameters
+    ----------
+    token:
+        Tibber API token.  **Never** logged or included in exception messages.
+    home_id:
+        If given, the home with this Tibber home ID is selected.  If ``None``,
+        the first home in the account is used.
+    timeout:
+        HTTP request timeout in seconds (default 15 s).
+
+    Returns
+    -------
+    list[PricePoint]
+        List of price points with UTC-aware ``starts_at`` values.
+
+    Raises
+    ------
+    TibberAuthError
+        If the token is rejected (HTTP 401/403).
+    TibberError
+        For network failures, timeouts, or unexpected API responses.
+    """
+    data = _post_graphql(token, _PRICE_RANGE_QUERY, timeout)
+
+    try:
+        homes = data["viewer"]["homes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response has unexpected shape") from exc
+
+    home = _pick_home(homes, home_id)
+
+    try:
+        nodes = home["currentSubscription"]["priceInfoRange"]["nodes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response missing priceInfoRange nodes") from exc
+
+    return [_parse_node(node, "QUARTER_HOURLY") for node in nodes]
+
+
+def fetch_current_price(
+    token: str,
+    home_id: str | None = None,
+    *,
+    timeout: float = _DEFAULT_TIMEOUT,
+) -> PricePoint:
+    """Fetch the *current* price point from the Tibber API.
+
+    Uses the lighter ``priceInfo { current { ... } }`` query rather than the
+    full range query, making it suitable for a fast connection test.
+
+    Parameters
+    ----------
+    token:
+        Tibber API token.  **Never** logged or included in exception messages.
+    home_id:
+        If given, the home with this Tibber home ID is selected.  If ``None``,
+        the first home in the account is used.
+    timeout:
+        HTTP request timeout in seconds (default 15 s).
+
+    Returns
+    -------
+    PricePoint
+        The current price point with a UTC-aware ``starts_at``.
+
+    Raises
+    ------
+    TibberAuthError
+        If the token is rejected (HTTP 401/403).
+    TibberError
+        For network failures, timeouts, missing current price, or unexpected
+        API responses.
+    """
+    data = _post_graphql(token, _CURRENT_PRICE_QUERY, timeout)
+
+    try:
+        homes = data["viewer"]["homes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response has unexpected shape") from exc
+
+    home = _pick_home(homes, home_id)
+
+    try:
+        current = home["currentSubscription"]["priceInfo"]["current"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response missing current price") from exc
+
+    if current is None:
+        raise TibberError("Tibber API returned null for current price")
+
+    return _parse_node(current, "QUARTER_HOURLY")
@@ -13,6 +13,11 @@ from sqlalchemy.orm import Session
 from app import models  # noqa: F401
 from app.api.routes.api.config import router as api_config_router
 from app.api.routes.api.data import router as api_data_router
+from app.api.routes.api.energy import router as api_energy_router
+from app.api.routes.api.energy_contracts import router as api_energy_contracts_router
+from app.api.routes.api.expose import router as api_expose_router
+from app.api.routes.api.meters import router as api_meters_router
+from app.api.routes.api.modbus import router as api_modbus_router
 from app.api.routes.api.session import router as api_session_router
 from app.api.routes import status
 from app.db import get_session_local
@@ -22,9 +27,15 @@ from app.api.routes.poo import router as poo_router
 from app.api.routes.public_ip import router as public_ip_router
 from app.api.routes.ticktick import router as ticktick_router
 from app.config import get_settings
+from app.integrations.mqtt import mqtt_manager
 from app.services.auth import AuthBootstrapError, initialize_auth_schema
-from app.services.config_page import seed_missing_config_from_bootstrap, sync_app_hostname_from_bootstrap
+from app.services.config_page import build_runtime_settings, seed_missing_config_from_bootstrap, sync_app_hostname_from_bootstrap
+from app.services.dsmr_ingest import apply_dsmr_subscription
 from app.services.public_ip import check_public_ipv4_and_notify
+from app.services.modbus_poll import poll_all_enabled_devices, BASE_POLL_TICK_SECONDS
+from app.services.ha_discovery import publish_discovery, publish_states
+from app.services.tibber_prices import refresh_prices
+from app.services.energy_cost import compute_closed_periods
 from scripts.app_db_adopt import AppDatabaseAdoptionError, validate_app_runtime_db

 logger = logging.getLogger(__name__)
@@ -48,6 +59,106 @@ def _run_scheduled_public_ip_check() -> None:
        session.close()


+def _run_scheduled_modbus_poll() -> None:
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        poll_all_enabled_devices(session, bootstrap_settings=get_settings())
+    finally:
+        session.close()
+
+
+def _run_scheduled_tibber_refresh() -> None:
+    """Scheduled job: fetch Tibber 15-minute prices and upsert into tibber_price.
+
+    Runs every hour so that:
+    - Today's prices are available from startup.
+    - Tomorrow's prices (published by Tibber around 13:00 CET / 11:00 UTC) are
+      picked up within an hour of publication without requiring a server restart.
+
+    The job is a no-op when:
+    - No active energy contract with kind="tibber" exists.
+    - The Tibber API token is empty in the runtime settings.
+
+    Any client exceptions (auth failures, network errors) are caught and logged
+    so that a single failed fetch does not crash the scheduler or affect the
+    other background jobs.
+    """
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        runtime_settings = build_runtime_settings(session, get_settings())
+        refresh_prices(session, runtime_settings)
+    except Exception:
+        logger.exception("_run_scheduled_tibber_refresh: unexpected error")
+    finally:
+        session.close()
+
+
+def _run_scheduled_energy_cost() -> None:
+    """Scheduled job: compute billing records for all uncalculated closed 15-minute periods.
+
+    Runs every minute so that a new period is picked up within 1 minute of
+    closing.  The job is a no-op when:
+    - No active energy contract with a version covering the period exists.
+    - DSMR data has not yet arrived for the period boundaries.
+    - The period's billing record already exists and is not degraded.
+
+    Any unexpected exceptions are caught and logged so that a single failure
+    does not crash the scheduler or affect the other background jobs.
+    """
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        compute_closed_periods(session)
+        # After billing periods are computed, push fresh energy-cost state values
+        # to MQTT/HA.  publish_states is internally guarded by _should_publish
+        # (MQTT disabled / not connected → no-op), so this never raises due to
+        # unconfigured MQTT and does not block the billing job.
+        try:
+            from app.services.ha_discovery import publish_states
+            publish_states(session)
+        except Exception:
+            logger.exception("_run_scheduled_energy_cost: publish_states failed (non-fatal)")
+    except Exception:
+        logger.exception("_run_scheduled_energy_cost: unexpected error")
+    finally:
+        session.close()
+
+
+def _run_scheduled_ha_state_publish() -> None:
+    """Periodic job: publish discovery configs + state + availability for all enabled exposed entities.
+
+    Runs every 60 seconds.  When the MQTT broker is connected:
+    - Publishes (or re-publishes) all HA Discovery configs (retained, idempotent).
+    - Publishes the current state / availability for all enabled entities.
+
+    This also serves as the reliable "publish discovery after connect" mechanism:
+    because paho connects asynchronously, a synchronous call immediately after
+    ``mqtt_manager.connect()`` would fire before the TCP handshake completes and
+    be a no-op.  Instead, this periodic job picks it up within 60 seconds of the
+    broker becoming available — retained payloads make repeated publishes harmless.
+
+    Additionally, if MQTT is configured in DB but the manager is not yet connected
+    (e.g. MQTT was enabled via UI after startup), this job attempts to connect so
+    the user does not need to restart the server.
+    """
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        runtime_settings = build_runtime_settings(session, get_settings())
+        # Reconnect if MQTT is configured (in DB) but not yet connected.
+        if mqtt_manager.is_configured(runtime_settings) and not mqtt_manager.is_connected:
+            logger.info("_run_scheduled_ha_state_publish: MQTT configured but not connected — attempting connect.")
+            mqtt_manager.connect(runtime_settings)
+        publish_discovery(session)
+        publish_states(session)
+    except Exception:
+        logger.exception("_run_scheduled_ha_state_publish: unexpected error")
+    finally:
+        session.close()
+
+
 def ensure_auth_db_ready() -> None:
    session_local = get_session_local()
    session: Session = session_local()
@@ -83,8 +194,69 @@ async def lifespan(_: FastAPI):
        max_instances=1,
        coalesce=True,
    )
+    scheduler.add_job(
+        _run_scheduled_modbus_poll,
+        trigger=IntervalTrigger(seconds=BASE_POLL_TICK_SECONDS),
+        id="modbus-poll",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
+    # Periodic HA state / availability publish (60-second fallback sweep).
+    scheduler.add_job(
+        _run_scheduled_ha_state_publish,
+        trigger=IntervalTrigger(seconds=60),
+        id="ha-state-publish",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
+    # Tibber price refresh: fetch today + tomorrow every hour.
+    # The job is a no-op when no active tibber contract or token is configured,
+    # so it is safe to register unconditionally.
+    scheduler.add_job(
+        _run_scheduled_tibber_refresh,
+        trigger=IntervalTrigger(hours=1),
+        id="tibber-refresh",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
+    # Energy cost billing: compute uncalculated closed 15-minute periods every minute.
+    # The job is a no-op when no active contract or DSMR data is present, so it is
+    # safe to register unconditionally.
+    scheduler.add_job(
+        _run_scheduled_energy_cost,
+        trigger=IntervalTrigger(minutes=1),
+        id="energy-cost",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
    scheduler.start()
+
+    # MQTT: connect using DB-merged runtime settings so broker configured via UI
+    # is picked up on restart (not just from env/bootstrap settings).
+    # Discovery will be published by the first run of _run_scheduled_ha_state_publish
+    # (within 60 s of startup), after the async paho handshake completes.
+    _startup_session_local = get_session_local()
+    _startup_session: Session = _startup_session_local()
+    try:
+        _startup_runtime_settings = build_runtime_settings(_startup_session, get_settings())
+    finally:
+        _startup_session.close()
+    mqtt_manager.connect(_startup_runtime_settings)
+
+    # DSMR ingest: subscribe to the configured MQTT topic when enabled.  The same
+    # applier is called from PUT /api/config, so toggling DSMR via the UI takes
+    # effect without an app restart.
+    apply_dsmr_subscription(_startup_runtime_settings)
+
    yield
+
+    # MQTT: clean shutdown before the process exits.
+    mqtt_manager.disconnect()
+
    scheduler.shutdown(wait=False)


@@ -107,6 +279,11 @@ def create_app() -> FastAPI:
    app.include_router(status.router)
    app.include_router(api_config_router)
    app.include_router(api_data_router)
+    app.include_router(api_energy_router)
+    app.include_router(api_energy_contracts_router)
+    app.include_router(api_meters_router)
+    app.include_router(api_expose_router)
+    app.include_router(api_modbus_router)
    app.include_router(api_session_router)
    app.include_router(homeassistant_router)
    app.include_router(location_router)
@@ -15,8 +15,12 @@ class AuthUser(Base):
    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    force_password_change: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    # TOTP fields (Phase B, M4-T04) — nullable/false by default so existing users are unaffected
+    totp_secret: Mapped[str | None] = mapped_column(String(64), nullable=True)
+    totp_enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)

    sessions: Mapped[list["AuthSession"]] = relationship(back_populates="user")
+    recovery_codes: Mapped[list["RecoveryCode"]] = relationship(back_populates="user")


 class AuthSession(Base):
@@ -31,3 +35,21 @@ class AuthSession(Base):
    revoked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    user: Mapped[AuthUser] = relationship(back_populates="sessions")
+
+
+class RecoveryCode(Base):
+    """One-time TOTP recovery codes for AuthUser.
+
+    ``code_hash`` stores the Argon2 hash of the plaintext code (plaintext is
+    returned only at setup time and never stored).  ``used_at`` is NULL while
+    the code is still valid; set to the consumption timestamp when consumed.
+    """
+
+    __tablename__ = "auth_recovery_code"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    user_id: Mapped[int] = mapped_column(ForeignKey("auth_users.id"), nullable=False, index=True)
+    code_hash: Mapped[str] = mapped_column(String(255), nullable=False)
+    used_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+
+    user: Mapped[AuthUser] = relationship(back_populates="recovery_codes")
@@ -0,0 +1,31 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, Index, Integer, String, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db import Base
+
+
+class LoginThrottle(Base):
+    """Tracks per-key login failure state for exponential back-off throttling.
+
+    ``scope`` is either ``'ip'`` or ``'user'``; ``key`` is the IP address or
+    username string respectively.  The pair ``(scope, key)`` is unique — one
+    row per tracked entity.  A row is deleted on successful login (clear).
+    """
+
+    __tablename__ = "auth_login_throttle"
+    __table_args__ = (
+        UniqueConstraint("scope", "key", name="uq_auth_login_throttle_scope_key"),
+        Index("ix_auth_login_throttle_scope_key", "scope", "key"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    key: Mapped[str] = mapped_column(String(255), nullable=False)
+    scope: Mapped[str] = mapped_column(String(16), nullable=False)  # 'ip' | 'user'
+    failures: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    first_failed_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    last_failed_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    next_allowed_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
@@ -0,0 +1,318 @@
+"""SQLAlchemy models for the energy pricing and DSMR metering subsystem.
+
+Six tables:
+  - meter:                    physical electricity meter lifecycle epoch.
+  - dsmr_reading:             raw DSMR telegram blobs (10-second down-sampled).
+  - energy_contract:          contract head (manual or tibber, one active at a time).
+  - energy_contract_version:  versioned pricing values; append-only for auditability.
+  - tibber_price:             cached Tibber 15-minute spot prices (immutable).
+  - energy_cost_period:       computed 15-minute billing periods (immutable snapshot).
+"""
+
+from __future__ import annotations
+
+import uuid as _uuid
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, Float, ForeignKey, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.types import JSON
+
+from app.db import Base
+
+
+def _uuid4_str() -> str:
+    return str(_uuid.uuid4())
+
+
+class Meter(Base):
+    """One physical electricity meter's installation epoch.
+
+    A ``meter`` record represents the period ``[started_at, ended_at)`` during
+    which a particular physical meter was installed and active.  Replacing a meter
+    (swap, home move, etc.) is modelled by closing the current record
+    (``ended_at = swap_timestamp``) and opening a new one
+    (``started_at = swap_timestamp``).
+
+    **Invariant**: for each ``commodity`` there is at most one active meter
+    (``ended_at IS NULL``) at any point in time.  The service layer enforces
+    this — no DB-level constraint is added to keep the migration simple and to
+    allow the application to return a meaningful error message.
+
+    ``commodity`` defaults to ``"electricity"``; the field is a free-form string
+    (no CHECK constraint) so future commodities (``gas``, ``heating``) can be
+    added without a schema change.
+
+    ``reason`` captures why this epoch started — one of ``initial``,
+    ``meter_swap``, ``home_move``, or ``other`` — stored as a plain string so
+    the application layer controls the allowed set.
+    """
+
+    __tablename__ = "meter"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # Stable internal identity — used as HA Discovery unique_id anchor.
+    uuid: Mapped[str] = mapped_column(
+        String(36), unique=True, nullable=False, default=_uuid4_str
+    )
+
+    # Human-readable label for this physical meter (e.g. address, serial, tariff zone).
+    label: Mapped[str] = mapped_column(String(255), nullable=False)
+
+    # Energy commodity this meter measures.  Defaults to "electricity".
+    commodity: Mapped[str] = mapped_column(String(32), nullable=False, default="electricity")
+
+    # UTC timestamp when this meter epoch starts (inclusive).  May be in the past
+    # (retroactive declaration); effective billing start = max(started_at, data start).
+    started_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    # UTC timestamp when this meter epoch ends (exclusive).  NULL = currently active.
+    ended_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+
+    # Why this epoch was created.  Application-layer validation enforces the
+    # allowed set; no CHECK constraint to keep migrations simple.
+    reason: Mapped[str] = mapped_column(String(64), nullable=False)
+
+    # Free-form note (e.g. location, physical meter id, reason details).
+    note: Mapped[str | None] = mapped_column(String(1024), nullable=True)
+
+    # UTC timestamp of when this row was created.
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    # Relationship to cost periods attributed to this meter epoch (not loaded eagerly).
+    cost_periods: Mapped[list["EnergyCostPeriod"]] = relationship(
+        back_populates="meter", cascade="save-update, merge"
+    )
+
+
+class DsmrReading(Base):
+    """One down-sampled DSMR telegram stored as a full JSON blob.
+
+    Identity & idempotency are **independent of the DSMR Reader's telegram id**
+    (that field overflows and must be manually reset to zero — a known DSMR
+    quirk — so relying on it for uniqueness risks silently dropping new data).
+    The table's own autoincrement ``id`` PK is the stable internal identity, and
+    ``recorded_at`` (the telegram timestamp) is the UNIQUE de-duplication key: a
+    single P1 meter emits exactly one telegram per timestamp.
+
+    ``recorded_at`` is a real column (not inside the payload) so time-range
+    queries are efficient.  The entire telegram frame is stored verbatim in
+    ``payload``; no field allow-list is applied so future commodities (gas,
+    heating, three-phase) are accommodated without a schema change.
+    """
+
+    __tablename__ = "dsmr_reading"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # UTC timestamp of the sample — real column, UNIQUE (telegram-id-independent
+    # idempotency key).  The unique index also serves time-range queries.
+    recorded_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, unique=True
+    )
+
+    # Telegram's own id (DSMR Reader assigns it).  Stored only as a reference /
+    # debugging aid — NOT used for uniqueness or idempotency (it overflows and
+    # gets reset to zero).  Nullable because some DSMR sources may not emit one.
+    source_id: Mapped[int | None] = mapped_column(Integer, nullable=True)
+
+    # Full telegram frame as a JSON object; values are typically JSON strings
+    # (e.g. "20915.154") — callers must cast to Decimal before arithmetic.
+    payload: Mapped[dict] = mapped_column(JSON, nullable=False)
+
+
+class EnergyContract(Base):
+    """Contract head: a named energy contract with a chosen pricing strategy.
+
+    ``kind`` determines which price strategy is used (``manual`` for fixed
+    dual-tariff rates entered by the user, ``tibber`` for dynamic API prices).
+    Only one contract may be ``active`` at a time; the service layer enforces
+    mutual exclusion.  Specific pricing values live in ``EnergyContractVersion``
+    so that price changes can be tracked without modifying historical records.
+    """
+
+    __tablename__ = "energy_contract"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # Human-readable label; freely editable by the user.
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+
+    # Strategy selector: "manual" or "tibber".  Application-layer validation
+    # enforces the allowed set; no DB CHECK constraint is added to keep the
+    # migration simple and the strategy registry extensible.
+    kind: Mapped[str] = mapped_column(String(32), nullable=False)
+
+    # Whether this is the currently active contract (at most one should be True).
+    active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+
+    # ISO 4217 currency code for all monetary values in this contract.
+    currency: Mapped[str] = mapped_column(String(8), nullable=False, default="EUR")
+
+    # Audit timestamps.
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    # Relationship to versions (back-reference; not loaded eagerly).
+    versions: Mapped[list["EnergyContractVersion"]] = relationship(
+        back_populates="contract", cascade="save-update, merge"
+    )
+
+
+class EnergyContractVersion(Base):
+    """One time-bounded version of an energy contract's pricing values.
+
+    Pricing changes are modelled as new versions (append-only); existing versions
+    are never modified so that historical ``EnergyCostPeriod`` records remain
+    fully auditable.  ``effective_to`` is ``NULL`` for the currently open version.
+    """
+
+    __tablename__ = "energy_contract_version"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # FK to the parent contract.  RESTRICT prevents deletion of a contract that
+    # still has versioned pricing rows attached to it.
+    contract_id: Mapped[int] = mapped_column(
+        ForeignKey("energy_contract.id", ondelete="RESTRICT"), nullable=False
+    )
+
+    # Start of this version's validity window (inclusive, UTC).
+    effective_from: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+
+    # End of this version's validity window (exclusive, UTC).  NULL means open-ended
+    # (i.e. this is the most recent / current version).
+    effective_to: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+
+    # Pricing values as a JSON object conforming to the profile structure for
+    # ``contract.kind`` (validated by the application layer against the YAML profile).
+    values: Mapped[dict] = mapped_column(JSON, nullable=False)
+
+    # Creation timestamp.
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    # Relationship back to the parent contract.
+    contract: Mapped["EnergyContract"] = relationship(back_populates="versions")
+
+    # Relationship to cost periods that reference this version.
+    cost_periods: Mapped[list["EnergyCostPeriod"]] = relationship(
+        back_populates="contract_version", cascade="save-update, merge"
+    )
+
+
+class TibberPrice(Base):
+    """Cached Tibber 15-minute spot price point (immutable once fetched).
+
+    ``starts_at`` is unique so that upserts are idempotent.  Past prices are
+    never overwritten; the fetch job only adds rows for future time slots.
+    """
+
+    __tablename__ = "tibber_price"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # UTC start of the 15-minute slot; unique so upsert is idempotent.
+    starts_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, unique=True
+    )
+
+    # Resolution label as returned by the Tibber API (e.g. "QUARTER_HOURLY").
+    resolution: Mapped[str] = mapped_column(String(32), nullable=False)
+
+    # Price components in the contract currency (all include VAT, user-facing).
+    energy: Mapped[float] = mapped_column(Float, nullable=False)
+    tax: Mapped[float] = mapped_column(Float, nullable=False)
+    total: Mapped[float] = mapped_column(Float, nullable=False)
+
+    # Tibber price level (e.g. "NORMAL", "CHEAP", "EXPENSIVE"); may be absent.
+    level: Mapped[str | None] = mapped_column(String(32), nullable=True)
+
+    # ISO 4217 currency code as returned by the API.
+    currency: Mapped[str] = mapped_column(String(8), nullable=False)
+
+    # UTC timestamp of when this row was fetched/inserted.
+    fetched_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+
+class EnergyCostPeriod(Base):
+    """Computed billing record for one 15-minute metering period (immutable snapshot).
+
+    Each row captures the per-register kWh deltas, the resulting import cost and
+    export revenue, and a full snapshot of the pricing values used so that the
+    calculation is fully auditable and reproducible without re-querying the
+    contract version.  Rows are written once and never modified; explicit
+    recomputation via the API is the only way to overwrite a period.
+    """
+
+    __tablename__ = "energy_cost_period"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # UTC start of the 15-minute period; unique so upsert is idempotent.
+    period_start: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, unique=True
+    )
+
+    # Per-register kWh deltas for the period (end minus start of cumulative registers).
+    # _1 = dal/low-tariff, _2 = normal/high-tariff (NL convention).
+    d1_kwh: Mapped[float] = mapped_column(Float, nullable=False)  # delivered low
+    d2_kwh: Mapped[float] = mapped_column(Float, nullable=False)  # delivered high
+    r1_kwh: Mapped[float] = mapped_column(Float, nullable=False)  # returned low
+    r2_kwh: Mapped[float] = mapped_column(Float, nullable=False)  # returned high
+
+    # Computed monetary amounts for the period (in ``currency``).
+    import_cost: Mapped[float] = mapped_column(Float, nullable=False)
+    export_revenue: Mapped[float] = mapped_column(Float, nullable=False)
+    net_cost: Mapped[float] = mapped_column(Float, nullable=False)
+
+    # ISO 4217 currency code matching the contract.
+    currency: Mapped[str] = mapped_column(String(8), nullable=False)
+
+    # Full snapshot of the pricing inputs used during computation.  This makes
+    # each row self-contained and auditable even if the contract is later changed.
+    pricing: Mapped[dict] = mapped_column(JSON, nullable=False)
+
+    # FK to the exact contract version whose values were used.  RESTRICT prevents
+    # deletion of a version that has cost records attached.  Nullable to support
+    # periods computed in ``degraded`` mode (missing price data).
+    contract_version_id: Mapped[int | None] = mapped_column(
+        ForeignKey("energy_contract_version.id", ondelete="RESTRICT"), nullable=True
+    )
+
+    # FK to the meter epoch this period belongs to.  RESTRICT prevents deletion of
+    # a meter that still has attributed cost periods.  Nullable for backwards
+    # compatibility (pre-M7 rows) and degraded periods where the meter was not
+    # determinable.
+    meter_id: Mapped[int | None] = mapped_column(
+        ForeignKey("meter.id", ondelete="RESTRICT"), nullable=True
+    )
+
+    # True when the period was computed with incomplete data (missing readings or
+    # missing price); serves as a flag for later recomputation.
+    degraded: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+
+    # UTC timestamp of when this row was computed/inserted.
+    computed_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    # Relationship back to the contract version.
+    contract_version: Mapped["EnergyContractVersion | None"] = relationship(
+        back_populates="cost_periods"
+    )
+
+    # Relationship back to the meter epoch.
+    meter: Mapped["Meter | None"] = relationship(back_populates="cost_periods")
+
+
+# Index on recorded_at for efficient time-range queries on DSMR readings.
+# (The ORM-level index=True on recorded_at already creates ix_dsmr_reading_recorded_at;
+# no composite index is needed for single-meter deployments.)
+
+# Index on period_start is covered by the unique constraint (SQLite creates an
+# implicit index for UNIQUE columns), so no additional index is required.
+
+# Index on starts_at for TibberPrice is covered by the unique constraint similarly.
@@ -0,0 +1,49 @@
+"""SQLAlchemy model for the exposed-entity toggle table.
+
+``ExposedEntityToggle`` stores the per-entity enable/disable state for the
+MQTT / HA Discovery expose framework.  The *catalog* of what *can* be
+exposed is computed dynamically by provider functions (see
+``app/integrations/expose.py``); this table only records which entries the
+user has explicitly enabled.
+
+Key design decisions
+--------------------
+- ``key`` is a stable string identifier derived from device uuid + metric key
+  (e.g. ``"modbus.<uuid>.voltage"``), so it does not drift if rows are
+  deleted and re-inserted.
+- Default state for an entity not yet in this table is **disabled** (false).
+  ``build_catalog`` in expose.py treats a missing row as ``enabled=False``.
+- Only one row per entity key (``key`` is UNIQUE).
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db import Base
+
+
+class ExposedEntityToggle(Base):
+    """Per-entity on/off switch for MQTT / HA Discovery publishing.
+
+    Rows are created on demand (first toggle); entities with no row are
+    treated as disabled.
+    """
+
+    __tablename__ = "exposed_entity_toggle"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # Stable entity key, e.g. "modbus.<uuid>.voltage" or "modbus.<uuid>.online".
+    key: Mapped[str] = mapped_column(String(255), unique=True, nullable=False)
+
+    # Whether this entity should be published via MQTT / HA Discovery.
+    enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+
+    # Last time this row was created or modified.
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
@@ -0,0 +1,114 @@
+"""SQLAlchemy models for Modbus device management and telemetry.
+
+Two tables:
+  - modbus_device: deployment/configurable metadata for each polled device.
+  - modbus_reading: generic telemetry rows (one per device per poll cycle).
+"""
+
+from __future__ import annotations
+
+import uuid as _uuid
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, Index, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.types import JSON
+
+from app.db import Base
+
+
+def _uuid4_str() -> str:
+    return str(_uuid.uuid4())
+
+
+class ModbusDevice(Base):
+    """Deployment-layer record for a Modbus slave device reachable via a TCP gateway.
+
+    Protocol knowledge (register map, decoding rules) lives in the YAML profile
+    referenced by ``profile``.  Per-device variables (network address, slave ID,
+    display name, poll rate) live here.
+    """
+
+    __tablename__ = "modbus_device"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # Stable internal identity — used as the API path key and HA Discovery unique_id anchor.
+    uuid: Mapped[str] = mapped_column(
+        String(36), unique=True, nullable=False, default=_uuid4_str
+    )
+
+    # Human-readable label (may be changed; changing it triggers re-publish of HA Discovery).
+    friendly_name: Mapped[str] = mapped_column(String(255), nullable=False)
+
+    # Transport protocol — only "tcp" is supported for now.
+    transport: Mapped[str] = mapped_column(String(16), nullable=False, default="tcp")
+
+    # TCP gateway address.
+    host: Mapped[str] = mapped_column(String(255), nullable=False)
+    port: Mapped[int] = mapped_column(Integer, nullable=False, default=502)
+
+    # Modbus slave address (set on the device panel; different meters on the same gateway
+    # must have distinct unit_ids).
+    unit_id: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
+
+    # Which YAML profile to use for register mapping and decoding (e.g. "sdm120").
+    profile: Mapped[str] = mapped_column(String(64), nullable=False)
+
+    # Polling interval in seconds.
+    poll_interval_s: Mapped[int] = mapped_column(Integer, nullable=False, default=5)
+
+    # Whether this device is included in the periodic poll sweep.
+    enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+
+    # Poll-status fields (updated by the poll service after each attempt).
+    last_poll_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+    last_poll_ok: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
+
+    # Audit timestamps.
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+
+    # Relationship to readings (back-reference; not loaded eagerly).
+    readings: Mapped[list["ModbusReading"]] = relationship(
+        back_populates="device", cascade="save-update, merge"
+    )
+
+
+class ModbusReading(Base):
+    """Generic telemetry row: one device, one poll instant, all decoded metrics as JSON.
+
+    ``payload`` contains the full dict of engineering values produced by the YAML profile
+    decoder, e.g. ``{"voltage": 230.2, "current": 1.3, ...}``.  The profile is the key
+    to interpreting which keys exist and what units they carry.
+    """
+
+    __tablename__ = "modbus_reading"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    # FK to the device that produced this reading.
+    # ON DELETE RESTRICT: prevents accidental deletion of a device that has historical data.
+    device_id: Mapped[int] = mapped_column(
+        ForeignKey("modbus_device.id", ondelete="RESTRICT"), nullable=False
+    )
+
+    # The UTC timestamp of when the sample was taken — real indexed column, NOT embedded in payload.
+    recorded_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, index=True
+    )
+
+    # Profile-decoded engineering values as a JSON object.
+    payload: Mapped[dict] = mapped_column(JSON, nullable=False)
+
+    device: Mapped["ModbusDevice"] = relationship(back_populates="readings")
+
+
+# Composite index for efficient time-range queries scoped to a single device.
+Index("ix_modbus_reading_device_recorded", ModbusReading.device_id, ModbusReading.recorded_at)
@@ -38,3 +38,10 @@ class SmtpTestResponse(BaseModel):

    result: Literal["success", "config-error", "failed"]
    message: str
+
+
+class MqttTestResponse(BaseModel):
+    """Response from POST /api/config/mqtt/test."""
+
+    result: Literal["success", "config-error", "failed"]
+    message: str
@@ -0,0 +1,216 @@
+"""Pydantic schemas for the Energy data API (M6-T09).
+
+Covers six endpoint groups under /api/energy:
+  - GET  /prices             — price curve (tibber 15min points or manual tariff)
+  - GET  /costs              — energy_cost_period rows (time-range, paginated)
+  - GET  /costs/summary      — aggregated metered + standing charges − credits
+  - GET  /dsmr/latest        — most recent dsmr_reading blob
+  - POST /costs/recompute    — explicit idempotent recompute (returns count)
+  - POST /tibber/test        — three-state Tibber connection test
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any, Literal
+
+from pydantic import BaseModel, Field
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/prices
+# ---------------------------------------------------------------------------
+
+
+class PricePointSchema(BaseModel):
+    """A single 15-minute price point (tibber) or placeholder entry."""
+
+    starts_at: datetime
+    buy: float = Field(description="All-in buy price in EUR/kWh (including taxes).")
+    sell: float = Field(description="Net sell price in EUR/kWh.")
+    level: str | None = Field(
+        default=None,
+        description="Tibber price level (CHEAP / NORMAL / EXPENSIVE); null for manual.",
+    )
+
+
+class ManualTariffSchema(BaseModel):
+    """Fixed-tariff breakdown for manual contracts.
+
+    Prices are the *effective* buy prices as used by the billing engine
+    (energy_buy_x + energy_tax + ode) and the raw sell prices.
+    """
+
+    buy_dal: float = Field(description="Effective buy price, low-tariff / dal (EUR/kWh).")
+    buy_normal: float = Field(description="Effective buy price, normal / high-tariff (EUR/kWh).")
+    sell_dal: float = Field(description="Sell price, low-tariff / dal (EUR/kWh).")
+    sell_normal: float = Field(description="Sell price, normal / high-tariff (EUR/kWh).")
+
+
+class PricesResponse(BaseModel):
+    """Response for GET /api/energy/prices.
+
+    ``kind`` mirrors the active contract kind:
+    - ``"tibber"``  → ``points`` has actual 15-min price entries; ``tariff`` is null.
+    - ``"manual"``  → ``points`` is empty; ``tariff`` carries the fixed-rate table.
+    - ``None``      → no active contract; both ``points`` and ``tariff`` are empty/null.
+
+    ``currency`` comes from the active contract (or "EUR" fallback).
+    ``points`` is always ascending by ``starts_at``.
+    """
+
+    kind: str | None = Field(
+        description="Active contract kind ('tibber' or 'manual'), or null if no active contract."
+    )
+    currency: str = Field(description="ISO 4217 currency code.")
+    points: list[PricePointSchema] = Field(
+        description=(
+            "15-minute price points for tibber contracts (ascending by starts_at). "
+            "Empty for manual contracts or when no active contract exists."
+        )
+    )
+    tariff: ManualTariffSchema | None = Field(
+        default=None,
+        description=(
+            "Fixed tariff table for manual contracts. "
+            "Null for tibber contracts and when no active contract exists."
+        ),
+    )
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/costs
+# ---------------------------------------------------------------------------
+
+
+class CostPeriodSchema(BaseModel):
+    """One 15-minute billing record from the energy_cost_period table."""
+
+    period_start: datetime
+    d1_kwh: float = Field(description="Delivered low-tariff kWh for this period.")
+    d2_kwh: float = Field(description="Delivered normal-tariff kWh for this period.")
+    r1_kwh: float = Field(description="Returned low-tariff kWh for this period.")
+    r2_kwh: float = Field(description="Returned normal-tariff kWh for this period.")
+    import_cost: float = Field(description="Cost of electricity drawn from grid (EUR).")
+    export_revenue: float = Field(description="Revenue from electricity fed to grid (EUR).")
+    net_cost: float = Field(description="import_cost − export_revenue (EUR).")
+    currency: str = Field(description="ISO 4217 currency code.")
+    degraded: bool = Field(
+        description="True when the period was computed with incomplete data."
+    )
+    contract_version_id: int | None = Field(
+        default=None,
+        description="FK to the contract version used for this billing period (null when degraded).",
+    )
+
+    model_config = {"from_attributes": True}
+
+
+class CostsResponse(BaseModel):
+    """Response for GET /api/energy/costs."""
+
+    items: list[CostPeriodSchema]
+    total: int = Field(description="Number of items returned.")
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/costs/summary
+# ---------------------------------------------------------------------------
+
+
+class SummaryResponse(BaseModel):
+    """Response for GET /api/energy/costs/summary.
+
+    All monetary values are in ``currency``.
+
+    ``total_payable = metered_net + fixed_costs − credits``
+    """
+
+    currency: str
+    metered_import: float = Field(description="Σ import_cost for non-degraded periods.")
+    metered_export: float = Field(description="Σ export_revenue for non-degraded periods.")
+    metered_net: float = Field(description="Σ net_cost for non-degraded periods.")
+    fixed_costs: float = Field(
+        description="Standing charges (network_fee + management_fee) apportioned over the interval."
+    )
+    credits: float = Field(
+        description="Energy-tax credit (heffingskorting) apportioned over the interval."
+    )
+    total_payable: float = Field(
+        description="metered_net + fixed_costs − credits (actual amount owed)."
+    )
+    period_count: int = Field(description="Number of non-degraded billing periods in range.")
+    degraded_count: int = Field(description="Number of degraded billing periods in range.")
+    days: float = Field(description="Interval length in days.")
+
+
+# ---------------------------------------------------------------------------
+# GET /api/energy/dsmr/latest
+# ---------------------------------------------------------------------------
+
+
+class DsmrLatestResponse(BaseModel):
+    """Response for GET /api/energy/dsmr/latest.
+
+    ``found`` is False when no dsmr_reading rows exist yet.  The front-end
+    should check ``found`` before reading ``recorded_at`` or ``payload``.
+    """
+
+    found: bool
+    recorded_at: datetime | None = None
+    payload: dict[str, Any] | None = None
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/costs/recompute
+# ---------------------------------------------------------------------------
+
+
+class RecomputeResponse(BaseModel):
+    """Response for POST /api/energy/costs/recompute."""
+
+    recomputed: int = Field(
+        description=(
+            "Number of 15-minute periods for which a billing record was written "
+            "(inserted or updated).  Periods skipped due to missing contract or "
+            "missing Tibber price are not counted."
+        )
+    )
+
+
+# ---------------------------------------------------------------------------
+# POST /api/energy/tibber/test
+# ---------------------------------------------------------------------------
+
+
+class TibberTestPriceSchema(BaseModel):
+    """Current Tibber price point returned on a successful test.
+
+    Carries enough fields for the front-end to confirm the API is working and
+    display the live price.  The API token is **never** included.
+    """
+
+    starts_at: datetime
+    total: float
+    energy: float
+    tax: float
+    currency: str
+    level: str | None = None
+
+
+class TibberTestResponse(BaseModel):
+    """Three-state response for POST /api/energy/tibber/test.
+
+    Possible ``result`` values:
+
+    - ``"success"``      — Tibber API responded with a valid price.
+    - ``"config-error"`` — Token is missing or not configured.
+    - ``"failed"``       — API call failed (auth rejected, network error, timeout, etc.).
+
+    ``price`` is populated only on ``"success"``; it is null otherwise.
+    ``message`` always contains a human-readable explanation.
+    """
+
+    result: Literal["success", "config-error", "failed"]
+    message: str
+    price: TibberTestPriceSchema | None = None
@@ -0,0 +1,148 @@
+"""Pydantic schemas for the EnergyContract CRUD + versioning API (M6-T04).
+
+Schema hierarchy
+----------------
+ContractVersionResponse   — single version row (id, dates, values, created_at)
+ContractResponse          — contract head (id, name, kind, active, currency, timestamps)
+ContractDetailResponse    — contract head + embedded versions list (for GET{id})
+ContractListResponse      — paginated list of ContractResponse items
+ContractCreate            — POST /api/energy/contracts body
+ContractPatch             — PATCH /api/energy/contracts/{id} body (all fields optional)
+VersionCreate             — POST /api/energy/contracts/{id}/versions body
+ProfilesResponse          — GET /api/energy/profiles response
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, Field
+
+
+# ---------------------------------------------------------------------------
+# Version schemas
+# ---------------------------------------------------------------------------
+
+
+class ContractVersionResponse(BaseModel):
+    """Response schema for a single EnergyContractVersion row."""
+
+    id: int
+    effective_from: datetime
+    effective_to: datetime | None
+    values: dict[str, Any]
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+# ---------------------------------------------------------------------------
+# Contract schemas
+# ---------------------------------------------------------------------------
+
+
+class ContractResponse(BaseModel):
+    """Response schema for a single EnergyContract (without embedded versions).
+
+    Used for list responses where embedding all versions would be expensive.
+    """
+
+    id: int
+    name: str
+    kind: str
+    active: bool
+    currency: str
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class ContractDetailResponse(BaseModel):
+    """Response schema for a single EnergyContract with full version history.
+
+    Returned by GET /api/energy/contracts/{id} and by successful POST / PATCH
+    operations where the caller needs to see all version data.
+    """
+
+    id: int
+    name: str
+    kind: str
+    active: bool
+    currency: str
+    created_at: datetime
+    updated_at: datetime
+    versions: list[ContractVersionResponse]
+
+    model_config = {"from_attributes": True}
+
+
+class ContractListResponse(BaseModel):
+    """Response schema for GET /api/energy/contracts."""
+
+    items: list[ContractResponse]
+    total: int
+
+
+# ---------------------------------------------------------------------------
+# Request schemas
+# ---------------------------------------------------------------------------
+
+
+class ContractCreate(BaseModel):
+    """Request body for POST /api/energy/contracts.
+
+    ``effective_from`` defaults to the current UTC time if not provided,
+    giving the first version an open-ended start from "now".
+    ``kind`` is validated at the application layer against the profile registry;
+    clients should send ``"manual"`` or ``"tibber"``.
+    """
+
+    name: str = Field(..., min_length=1, max_length=255)
+    kind: str = Field(..., min_length=1, max_length=32)
+    currency: str = Field(default="EUR", min_length=1, max_length=8)
+    values: dict[str, Any]
+    effective_from: datetime | None = Field(
+        default=None,
+        description=(
+            "UTC datetime from which the first pricing version is effective. "
+            "Defaults to the current UTC time when omitted."
+        ),
+    )
+
+
+class ContractPatch(BaseModel):
+    """Request body for PATCH /api/energy/contracts/{id}.
+
+    All fields are optional.  Sending ``active=true`` activates this contract
+    (deactivating all others); ``active=false`` deactivates it without affecting
+    other contracts.
+    """
+
+    name: str | None = Field(default=None, min_length=1, max_length=255)
+    active: bool | None = None
+
+
+class VersionCreate(BaseModel):
+    """Request body for POST /api/energy/contracts/{id}/versions."""
+
+    effective_from: datetime
+    values: dict[str, Any]
+
+
+# ---------------------------------------------------------------------------
+# Profile response schemas
+# ---------------------------------------------------------------------------
+
+
+class ProfilesResponse(BaseModel):
+    """Response schema for GET /api/energy/profiles.
+
+    ``profiles`` is a list of raw profile dicts as produced by
+    ``list_profiles()`` (Pydantic model dumps).  Each entry contains at minimum
+    ``kind`` and ``label``; the full nested structure allows the front-end to
+    render a type-appropriate form for each pricing profile.
+    """
+
+    profiles: list[dict[str, Any]]
@@ -0,0 +1,95 @@
+"""Pydantic schemas for the Expose API (M5-T12).
+
+Three endpoints:
+  GET  /api/expose           — catalog + toggle state + MQTT/Discovery status
+  PUT  /api/expose           — set toggles (map key → bool)
+  POST /api/expose/republish — trigger discovery re-publish
+"""
+
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+# ---------------------------------------------------------------------------
+# Nested schemas
+# ---------------------------------------------------------------------------
+
+
+class DeviceInfoSchema(BaseModel):
+    """HA device grouping info for an exposable entity."""
+
+    identifiers: list[str]
+    name: str
+
+
+class ExposableEntitySchema(BaseModel):
+    """One exposable entity in the catalog.
+
+    ``value_getter`` is intentionally excluded — it is a non-serialisable
+    callable and is only used internally by the HA Discovery service.
+    """
+
+    key: str
+    component: str
+    device: DeviceInfoSchema
+    device_class: str | None
+    unit: str
+    name: str
+    state_class: str | None = None
+
+
+class CatalogEntrySchema(BaseModel):
+    """An entity from the catalog with its current toggle state."""
+
+    entity: ExposableEntitySchema
+    enabled: bool
+
+
+class MqttStatusSchema(BaseModel):
+    """Connection status for MQTT and HA Discovery."""
+
+    mqtt_configured: bool
+    mqtt_connected: bool
+    discovery_enabled: bool
+
+
+# ---------------------------------------------------------------------------
+# Response schemas
+# ---------------------------------------------------------------------------
+
+
+class ExposeResponse(BaseModel):
+    """Response for GET /api/expose."""
+
+    catalog: list[CatalogEntrySchema]
+    mqtt_status: MqttStatusSchema
+
+
+class ExposeUpdateResponse(BaseModel):
+    """Response for PUT /api/expose (returns updated catalog + status)."""
+
+    catalog: list[CatalogEntrySchema]
+    mqtt_status: MqttStatusSchema
+
+
+class RepublishResponse(BaseModel):
+    """Response for POST /api/expose/republish."""
+
+    ok: bool
+    message: str
+
+
+# ---------------------------------------------------------------------------
+# Request schemas
+# ---------------------------------------------------------------------------
+
+
+class ExposeUpdateRequest(BaseModel):
+    """Request body for PUT /api/expose.
+
+    ``toggles`` is a map from entity key to desired enabled state (bool).
+    Only keys present in the map are updated; absent keys are untouched.
+    """
+
+    toggles: dict[str, bool]
@@ -0,0 +1,131 @@
+"""Pydantic schemas for the Meter CRUD + swap declaration API (M7-T05).
+
+Schema hierarchy
+----------------
+MeterResponse         — single meter row (id/label/commodity/started_at/ended_at/reason/note/created_at)
+MeterListResponse     — ordered list of MeterResponse items
+MeterDeclareRequest   — POST /api/energy/meters body (declare a swap or initial meter)
+MeterPatchRequest     — PATCH /api/energy/meters/{id} body (all fields optional)
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+from enum import Enum
+
+from pydantic import BaseModel, Field
+
+
+# ---------------------------------------------------------------------------
+# Enums
+# ---------------------------------------------------------------------------
+
+
+class MeterReason(str, Enum):
+    """Allowed values for the meter epoch creation reason."""
+
+    initial = "initial"
+    meter_swap = "meter_swap"
+    home_move = "home_move"
+    other = "other"
+
+
+# ---------------------------------------------------------------------------
+# Response schemas
+# ---------------------------------------------------------------------------
+
+
+class MeterResponse(BaseModel):
+    """Response schema for a single Meter epoch row.
+
+    ``ended_at`` is ``null`` for the currently active meter.
+    """
+
+    id: int
+    label: str
+    commodity: str
+    started_at: datetime
+    ended_at: datetime | None
+    reason: str
+    note: str | None
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class MeterListResponse(BaseModel):
+    """Response schema for GET /api/energy/meters.
+
+    Meters are returned in ascending ``started_at`` order so the caller sees
+    the historical installation sequence.
+    """
+
+    items: list[MeterResponse]
+    total: int
+
+
+# ---------------------------------------------------------------------------
+# Request schemas
+# ---------------------------------------------------------------------------
+
+_VALID_REASONS = ", ".join(r.value for r in MeterReason)
+
+
+class MeterDeclareRequest(BaseModel):
+    """Request body for POST /api/energy/meters.
+
+    Declares a new meter epoch (swap, home move, or initial declaration).  The
+    service layer closes the current active meter for the given commodity at
+    ``started_at`` and opens a new one.
+
+    ``started_at`` follows the Principle-A localisation convention: a
+    timezone-naive value is interpreted as the **server's local wall-clock time**
+    (e.g. CEST midnight → stored as UTC the night before); a timezone-aware
+    value is converted to UTC as-is.  Omitting ``started_at`` is not allowed —
+    every meter declaration must carry an explicit start timestamp.
+
+    ``commodity`` defaults to ``"electricity"``; the field is available for
+    future use with ``gas`` or ``heating``.
+    """
+
+    label: str = Field(..., min_length=1, max_length=255)
+    started_at: datetime = Field(
+        ...,
+        description=(
+            "UTC (or server-local naive) datetime from which this meter epoch starts.  "
+            "May be in the past (retroactive declaration)."
+        ),
+    )
+    reason: MeterReason = Field(
+        ...,
+        description=f"Why this epoch was created.  One of: {_VALID_REASONS}.",
+    )
+    note: str | None = Field(default=None, max_length=1024)
+    commodity: str = Field(
+        default="electricity",
+        min_length=1,
+        max_length=32,
+        description="Energy commodity this meter measures.  Defaults to 'electricity'.",
+    )
+
+
+class MeterPatchRequest(BaseModel):
+    """Request body for PATCH /api/energy/meters/{id}.
+
+    All fields are optional.  Only non-``None`` values are applied.
+
+    Updating ``started_at`` is a **retroactive correction**: the service layer
+    maintains timeline continuity (adjusting the preceding meter's ``ended_at``)
+    and the API layer triggers ``recompute_range`` over the affected window so
+    that billing attribution is re-judged.
+    """
+
+    label: str | None = Field(default=None, min_length=1, max_length=255)
+    note: str | None = Field(default=None, max_length=1024)
+    started_at: datetime | None = Field(
+        default=None,
+        description=(
+            "Retroactive correction of the meter epoch start timestamp.  "
+            "Triggers billing recompute over the affected window."
+        ),
+    )
@@ -0,0 +1,171 @@
+"""Pydantic schemas for the Modbus device CRUD + readings + metrics API (M5-T05)."""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, Field
+
+
+# ---------------------------------------------------------------------------
+# Device schemas
+# ---------------------------------------------------------------------------
+
+
+class ModbusDeviceCreate(BaseModel):
+    """Request body for POST /api/modbus/devices."""
+
+    friendly_name: str = Field(..., min_length=1, max_length=255)
+    transport: str = Field(default="tcp", max_length=16)
+    host: str = Field(..., min_length=1, max_length=255)
+    port: int = Field(default=502, ge=1, le=65535)
+    unit_id: int = Field(default=1, ge=0, le=247)
+    profile: str = Field(..., min_length=1, max_length=64)
+    poll_interval_s: int = Field(default=5, ge=1, le=3600)
+    enabled: bool = Field(default=True)
+
+
+class ModbusDeviceUpdate(BaseModel):
+    """Request body for PATCH /api/modbus/devices/{uuid} — all fields optional."""
+
+    friendly_name: str | None = Field(default=None, min_length=1, max_length=255)
+    transport: str | None = Field(default=None, max_length=16)
+    host: str | None = Field(default=None, min_length=1, max_length=255)
+    port: int | None = Field(default=None, ge=1, le=65535)
+    unit_id: int | None = Field(default=None, ge=0, le=247)
+    profile: str | None = Field(default=None, min_length=1, max_length=64)
+    poll_interval_s: int | None = Field(default=None, ge=1, le=3600)
+    enabled: bool | None = None
+
+
+class ModbusDeviceResponse(BaseModel):
+    """Response schema for a single Modbus device."""
+
+    uuid: str
+    friendly_name: str
+    transport: str
+    host: str
+    port: int
+    unit_id: int
+    profile: str
+    poll_interval_s: int
+    enabled: bool
+    last_poll_at: datetime | None
+    last_poll_ok: bool | None
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class ModbusDeviceListResponse(BaseModel):
+    """Response schema for listing Modbus devices."""
+
+    items: list[ModbusDeviceResponse]
+    total: int
+
+
+# ---------------------------------------------------------------------------
+# Reading schemas
+# ---------------------------------------------------------------------------
+
+
+class ModbusReadingResponse(BaseModel):
+    """A single reading row: timestamp + decoded payload."""
+
+    recorded_at: datetime
+    payload: dict[str, Any]
+
+    model_config = {"from_attributes": True}
+
+
+class ModbusReadingsResponse(BaseModel):
+    """Response schema for the readings time-range endpoint."""
+
+    items: list[ModbusReadingResponse]
+
+
+class ModbusLatestResponse(BaseModel):
+    """Response for the /latest endpoint.
+
+    ``found`` is False and ``recorded_at``/``payload`` are None when the device
+    has no readings yet.  Callers should check ``found`` before using the values.
+    """
+
+    found: bool
+    recorded_at: datetime | None
+    payload: dict[str, Any] | None
+
+
+# ---------------------------------------------------------------------------
+# Metrics / profile schemas
+# ---------------------------------------------------------------------------
+
+
+class MetricInfo(BaseModel):
+    """Metadata for a single measurable quantity in a device's profile."""
+
+    key: str
+    label: str
+    unit: str
+    device_class: str
+
+
+class ModbusMetricsResponse(BaseModel):
+    """Response schema for GET /api/modbus/devices/{uuid}/metrics."""
+
+    profile: str
+    metrics: list[MetricInfo]
+
+
+# ---------------------------------------------------------------------------
+# Profile list schema
+# ---------------------------------------------------------------------------
+
+
+class ProfileSummary(BaseModel):
+    """One entry in the GET /api/modbus/profiles response."""
+
+    name: str
+    description: str
+
+
+class ModbusProfilesResponse(BaseModel):
+    """Response schema for GET /api/modbus/profiles."""
+
+    profiles: list[ProfileSummary]
+
+
+# ---------------------------------------------------------------------------
+# Test-read schema
+# ---------------------------------------------------------------------------
+
+
+class ModbusTestReadResponse(BaseModel):
+    """Response for POST /api/modbus/devices/{uuid}/test.
+
+    On success ``ok=True`` and ``payload`` contains the decoded values.
+    On failure ``ok=False`` and ``error`` describes the problem.
+    """
+
+    ok: bool
+    payload: dict[str, Any] | None = None
+    error: str | None = None
+
+
+# ---------------------------------------------------------------------------
+# Cascade-delete schema
+# ---------------------------------------------------------------------------
+
+
+class ModbusDeleteResponse(BaseModel):
+    """Response for DELETE /api/modbus/devices/{uuid}?cascade=true.
+
+    Returned only when cascade deletion succeeds (HTTP 200).  Non-cascade
+    successful deletes continue to return HTTP 204 (no body).
+    """
+
+    deleted: bool
+    readings_deleted: int
+    toggles_deleted: int
@@ -16,6 +16,7 @@ class SessionResponse(BaseModel):
 class LoginRequest(BaseModel):
    username: str
    password: str
+    totp_code: str | None = None


 class PasswordChangeRequest(BaseModel):
@@ -0,0 +1,59 @@
+"""Pydantic schemas for TOTP setup / enable / disable / status endpoints (M4-T05)."""
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+# ---------------------------------------------------------------------------
+# Setup (POST /api/auth/totp/setup) — response
+# ---------------------------------------------------------------------------
+
+
+class TotpSetupResponse(BaseModel):
+    """Returned once after a setup call.
+
+    ``secret`` and ``recovery_codes`` are **one-time plaintext values**.
+    They are never returned again by any subsequent API call.
+    The frontend must display and instruct the user to save them before confirming.
+    """
+
+    secret: str
+    otpauth_uri: str
+    recovery_codes: list[str]
+
+
+# ---------------------------------------------------------------------------
+# Enable (POST /api/auth/totp/enable) — request
+# ---------------------------------------------------------------------------
+
+
+class TotpEnableRequest(BaseModel):
+    """The user confirms setup by providing the 6-digit TOTP code."""
+
+    code: str
+
+
+# ---------------------------------------------------------------------------
+# Disable (POST /api/auth/totp/disable) — request
+# ---------------------------------------------------------------------------
+
+
+class TotpDisableRequest(BaseModel):
+    """Disable TOTP by proving identity.
+
+    Exactly one of ``password`` or ``code`` must be provided.
+    """
+
+    password: str | None = None
+    code: str | None = None
+
+
+# ---------------------------------------------------------------------------
+# Status (GET /api/auth/totp) — response
+# ---------------------------------------------------------------------------
+
+
+class TotpStatusResponse(BaseModel):
+    """Minimal status response — never exposes secret or recovery codes."""
+
+    enabled: bool
@@ -25,9 +25,9 @@ class ConfigField:
 CONFIG_FIELDS: tuple[ConfigField, ...] = (
    ConfigField("System", "APP_NAME", "app_name", "App Name"),
    ConfigField("System", "APP_ENV", "app_env", "App Env"),
-    ConfigField("System", "APP_DEBUG", "app_debug", "App Debug"),
+    ConfigField("System", "APP_DEBUG", "app_debug", "App Debug", input_type="checkbox"),
    ConfigField("System", "APP_HOSTNAME", "app_hostname", "App Hostname"),
-    ConfigField("SMTP", "SMTP_ENABLED", "smtp_enabled", "SMTP Enabled"),
+    ConfigField("SMTP", "SMTP_ENABLED", "smtp_enabled", "SMTP Enabled", input_type="checkbox"),
    ConfigField("SMTP", "SMTP_HOST", "smtp_host", "SMTP Host"),
    ConfigField("SMTP", "SMTP_PORT", "smtp_port", "SMTP Port"),
    ConfigField("SMTP", "SMTP_USERNAME", "smtp_username", "SMTP Username"),
@@ -35,7 +35,7 @@ CONFIG_FIELDS: tuple[ConfigField, ...] = (
    ConfigField("SMTP", "SMTP_FROM_NAME", "smtp_from_name", "SMTP From Name"),
    ConfigField("SMTP", "SMTP_FROM_ADDRESS", "smtp_from_address", "SMTP From Address"),
    ConfigField("SMTP", "SMTP_TO_ADDRESS", "smtp_to_address", "SMTP To Address"),
-    ConfigField("SMTP", "SMTP_USE_STARTTLS", "smtp_use_starttls", "SMTP Use STARTTLS"),
+    ConfigField("SMTP", "SMTP_USE_STARTTLS", "smtp_use_starttls", "SMTP Use STARTTLS", input_type="checkbox"),
    ConfigField(
        "Authentication",
        "AUTH_SESSION_COOKIE_NAME",
@@ -49,6 +49,13 @@ CONFIG_FIELDS: tuple[ConfigField, ...] = (
        "auth_cookie_secure_override",
        "Cookie Secure Override",
    ),
+    ConfigField(
+        "Authentication",
+        "AUTH_LOGIN_THROTTLE_ENABLED",
+        "auth_login_throttle_enabled",
+        "Login Throttle Enabled",
+        input_type="checkbox",
+    ),
    ConfigField("Poo", "POO_WEBHOOK_ID", "poo_webhook_id", "Poo Webhook ID", secret=True),
    ConfigField(
        "Poo",
@@ -96,6 +103,61 @@ CONFIG_FIELDS: tuple[ConfigField, ...] = (
        "home_assistant_action_task_project_id",
        "Home Assistant Action Task Project ID",
    ),
+    ConfigField("MQTT", "MQTT_ENABLED", "mqtt_enabled", "MQTT Enabled", input_type="checkbox"),
+    ConfigField("MQTT", "MQTT_BROKER_HOST", "mqtt_broker_host", "MQTT Broker Host"),
+    ConfigField("MQTT", "MQTT_BROKER_PORT", "mqtt_broker_port", "MQTT Broker Port", input_type="number"),
+    ConfigField("MQTT", "MQTT_USERNAME", "mqtt_username", "MQTT Username"),
+    ConfigField("MQTT", "MQTT_PASSWORD", "mqtt_password", "MQTT Password", secret=True),
+    ConfigField("MQTT", "MQTT_TLS_ENABLED", "mqtt_tls_enabled", "MQTT TLS Enabled", input_type="checkbox"),
+    ConfigField(
+        "Home Assistant Discovery",
+        "HA_DISCOVERY_ENABLED",
+        "ha_discovery_enabled",
+        "HA Discovery Enabled",
+        input_type="checkbox",
+    ),
+    ConfigField(
+        "Home Assistant Discovery",
+        "HA_DISCOVERY_PREFIX",
+        "ha_discovery_prefix",
+        "HA Discovery Prefix",
+    ),
+    ConfigField(
+        "Home Assistant Discovery",
+        "HA_STATE_TOPIC_PREFIX",
+        "ha_state_topic_prefix",
+        "HA State Topic Prefix",
+    ),
+    ConfigField("Modbus", "MODBUS_POLLING_ENABLED", "modbus_polling_enabled", "Modbus Polling Enabled", input_type="checkbox"),
+    ConfigField(
+        "DSMR",
+        "DSMR_INGEST_ENABLED",
+        "dsmr_ingest_enabled",
+        "DSMR Ingest Enabled",
+        input_type="checkbox",
+    ),
+    ConfigField("DSMR", "DSMR_MQTT_TOPIC", "dsmr_mqtt_topic", "DSMR MQTT Topic"),
+    ConfigField(
+        "DSMR",
+        "DSMR_SAMPLE_INTERVAL_S",
+        "dsmr_sample_interval_s",
+        "DSMR Sample Interval (s)",
+        input_type="number",
+    ),
+    ConfigField(
+        "DSMR",
+        "DSMR_TARIFF_TOPIC",
+        "dsmr_tariff_topic",
+        "DSMR Tariff Topic",
+    ),
+    ConfigField(
+        "Tibber",
+        "TIBBER_API_TOKEN",
+        "tibber_api_token",
+        "Tibber API Token",
+        secret=True,
+    ),
+    ConfigField("Tibber", "TIBBER_HOME_ID", "tibber_home_id", "Tibber Home ID"),
 )


@@ -284,4 +346,22 @@ def _settings_payload(settings: Settings) -> dict[str, Any]:
        "auth_session_cookie_name": settings.auth_session_cookie_name,
        "auth_session_ttl_hours": settings.auth_session_ttl_hours,
        "auth_cookie_secure_override": settings.auth_cookie_secure_override,
+        "auth_login_throttle_enabled": settings.auth_login_throttle_enabled,
+        "auth_trust_forwarded_for": settings.auth_trust_forwarded_for,
+        "modbus_polling_enabled": settings.modbus_polling_enabled,
+        "mqtt_enabled": settings.mqtt_enabled,
+        "mqtt_broker_host": settings.mqtt_broker_host,
+        "mqtt_broker_port": settings.mqtt_broker_port,
+        "mqtt_username": settings.mqtt_username,
+        "mqtt_password": settings.mqtt_password,
+        "mqtt_tls_enabled": settings.mqtt_tls_enabled,
+        "ha_discovery_enabled": settings.ha_discovery_enabled,
+        "ha_discovery_prefix": settings.ha_discovery_prefix,
+        "ha_state_topic_prefix": settings.ha_state_topic_prefix,
+        "dsmr_ingest_enabled": settings.dsmr_ingest_enabled,
+        "dsmr_mqtt_topic": settings.dsmr_mqtt_topic,
+        "dsmr_sample_interval_s": settings.dsmr_sample_interval_s,
+        "dsmr_tariff_topic": settings.dsmr_tariff_topic,
+        "tibber_api_token": settings.tibber_api_token,
+        "tibber_home_id": settings.tibber_home_id,
    }
@@ -0,0 +1,364 @@
+"""Service layer for EnergyContract CRUD, versioning, and activation.
+
+All functions accept an explicit SQLAlchemy Session; callers are responsible
+for committing or rolling back the transaction.
+
+Design decisions
+----------------
+- ``create_contract``:   validates values against the pricing profile *before*
+  writing any rows; raises ``ProfileValidationError`` on non-compliance.
+- ``add_version``:       append-only; closes the previous open version by
+  setting its ``effective_to`` to the new version's ``effective_from``; raises
+  ``ContractVersionError`` if the new date is strictly earlier than the previous
+  version's ``effective_from``.
+- ``activate_contract``: mutual-exclusion; sets all other contracts' ``active``
+  to False, then sets the given contract's ``active`` to True.
+- ``active_contract_version_at``: returns the single version of the currently
+  active contract that covers *ts* (``effective_from ≤ ts < effective_to``,
+  or open-ended when ``effective_to`` is None).
+
+SQLite timezone note
+--------------------
+SQLite stores ``DateTime(timezone=True)`` columns as naive UTC strings; on
+read-back they come out as **timezone-naive** datetimes.  Wherever this code
+compares timestamps from the DB against timezone-aware values (e.g. from
+Pydantic or ``datetime.now(UTC)``), it calls ``_as_utc()`` to make both sides
+comparable without tripping on "offset-naive vs offset-aware" TypeErrors.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+from typing import Any
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.integrations.pricing.profiles import validate_values
+from app.models.energy import EnergyContract, EnergyContractVersion
+
+logger = logging.getLogger(__name__)
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _as_utc(dt: datetime) -> datetime:
+    """Return *dt* as a timezone-aware UTC datetime.
+
+    SQLite's DateTime(timezone=True) column type stores datetimes as naive UTC
+    strings and gives them back as naive datetimes on read.  This helper
+    re-attaches the UTC timezone info when it is missing, making cross-origin
+    comparisons safe.
+    """
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=UTC)
+    return dt
+
+
+# ---------------------------------------------------------------------------
+# Custom exception
+# ---------------------------------------------------------------------------
+
+
+class ContractVersionError(ValueError):
+    """Raised when a new contract version has an invalid effective date.
+
+    Specifically: the new version's ``effective_from`` must be greater than or
+    equal to the previous open version's ``effective_from``.  Allowing equal
+    timestamps would cause ambiguous overlap; the service therefore also rejects
+    strictly-equal values (same second) to avoid silent data loss.
+    """
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def get_contract_or_none(session: Session, contract_id: int) -> EnergyContract | None:
+    """Return the contract with the given id, or None if not found."""
+    return session.execute(
+        select(EnergyContract).where(EnergyContract.id == contract_id)
+    ).scalar_one_or_none()
+
+
+def list_contracts(session: Session) -> list[EnergyContract]:
+    """Return all contracts ordered by id (ascending)."""
+    return list(
+        session.execute(select(EnergyContract).order_by(EnergyContract.id)).scalars().all()
+    )
+
+
+def _open_version(session: Session, contract: EnergyContract) -> EnergyContractVersion | None:
+    """Return the current open version (effective_to IS NULL) for *contract*, or None."""
+    return session.execute(
+        select(EnergyContractVersion)
+        .where(
+            EnergyContractVersion.contract_id == contract.id,
+            EnergyContractVersion.effective_to.is_(None),
+        )
+        .order_by(EnergyContractVersion.effective_from.desc())
+        .limit(1)
+    ).scalar_one_or_none()
+
+
+# ---------------------------------------------------------------------------
+# Core service functions
+# ---------------------------------------------------------------------------
+
+
+def create_contract(
+    session: Session,
+    *,
+    name: str,
+    kind: str,
+    currency: str = "EUR",
+    values: dict[str, Any],
+    effective_from: datetime,
+) -> EnergyContract:
+    """Create a new energy contract with its first pricing version.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  Caller must commit after this returns.
+    name:
+        Human-readable label for the contract.
+    kind:
+        Pricing strategy identifier (``"manual"`` or ``"tibber"``).
+    currency:
+        ISO 4217 currency code (default ``"EUR"``).
+    values:
+        Pricing values dict conforming to the named profile's structure.
+        Validated via ``validate_values(kind, values)`` before any writes.
+    effective_from:
+        UTC datetime at which the first pricing version takes effect.
+
+    Returns
+    -------
+    EnergyContract
+        The newly created contract (not yet committed).
+
+    Raises
+    ------
+    ProfileNotFoundError
+        If no YAML profile exists for *kind*.
+    ProfileValidationError
+        If *values* does not conform to the profile structure.
+    """
+    # Validate (and fill defaults) before any DB write.
+    filled_values = validate_values(kind, values)
+
+    now = datetime.now(UTC)
+    contract = EnergyContract(
+        name=name,
+        kind=kind,
+        currency=currency,
+        active=False,  # New contracts are inactive; caller must explicitly activate.
+        created_at=now,
+        updated_at=now,
+    )
+    session.add(contract)
+    session.flush()  # Assign contract.id so we can reference it in the version FK.
+
+    version = EnergyContractVersion(
+        contract_id=contract.id,
+        effective_from=effective_from,
+        effective_to=None,
+        values=filled_values,
+        created_at=now,
+    )
+    session.add(version)
+
+    logger.info("Created energy contract %r (kind=%s, id=%d)", name, kind, contract.id)
+    return contract
+
+
+def add_version(
+    session: Session,
+    contract: EnergyContract,
+    *,
+    effective_from: datetime,
+    values: dict[str, Any],
+) -> EnergyContractVersion:
+    """Add a new pricing version to an existing contract (append-only).
+
+    The previous open version's ``effective_to`` is automatically set to the
+    new version's ``effective_from`` (version closure), ensuring there is never
+    a gap or overlap between consecutive versions.
+
+    The new ``effective_from`` **must be strictly greater than** the previous
+    open version's ``effective_from``.  Equal timestamps are rejected because
+    they would produce two versions starting at the same instant, making it
+    impossible to determine which is current.  If this constraint is not met,
+    ``ContractVersionError`` is raised and **no rows are written**.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  Caller must commit after this returns.
+    contract:
+        The parent ``EnergyContract`` to append a version to.
+    effective_from:
+        UTC datetime at which this version's pricing takes effect.
+    values:
+        New pricing values dict conforming to the contract's profile.
+
+    Returns
+    -------
+    EnergyContractVersion
+        The newly created version (not yet committed).
+
+    Raises
+    ------
+    ContractVersionError
+        If *effective_from* is not strictly after the previous open version's
+        ``effective_from``.
+    ProfileNotFoundError
+        If no YAML profile exists for the contract's kind.
+    ProfileValidationError
+        If *values* does not conform to the profile structure.
+    """
+    # Validate (and fill defaults) before any DB write.
+    filled_values = validate_values(contract.kind, values)
+
+    prev = _open_version(session, contract)
+    if prev is not None:
+        # Enforce strictly-after constraint to prevent ambiguous overlap.
+        # Use _as_utc() on both sides: the incoming value may be tz-aware
+        # while the DB-read value is tz-naive (SQLite limitation).
+        if _as_utc(effective_from) <= _as_utc(prev.effective_from):
+            raise ContractVersionError(
+                f"New version effective_from ({effective_from.isoformat()}) must be strictly "
+                f"after the previous open version's effective_from "
+                f"({prev.effective_from.isoformat()})."
+            )
+        # Close the previous open version.
+        prev.effective_to = effective_from
+
+    now = datetime.now(UTC)
+    new_version = EnergyContractVersion(
+        contract_id=contract.id,
+        effective_from=effective_from,
+        effective_to=None,
+        values=filled_values,
+        created_at=now,
+    )
+    session.add(new_version)
+
+    logger.info(
+        "Added version to contract id=%d (kind=%s, effective_from=%s)",
+        contract.id,
+        contract.kind,
+        effective_from.isoformat(),
+    )
+    return new_version
+
+
+def activate_contract(session: Session, contract: EnergyContract) -> None:
+    """Activate a contract with mutual exclusion.
+
+    Sets every other contract's ``active`` flag to False, then sets the given
+    contract's ``active`` to True.  This guarantees at most one active contract
+    at any time.
+
+    Caller must commit after this returns.
+    """
+    # Deactivate all contracts (including the target; we re-activate below).
+    for other in session.execute(select(EnergyContract)).scalars().all():
+        other.active = False
+    contract.active = True
+    contract.updated_at = datetime.now(UTC)
+    logger.info("Activated contract %r (id=%d)", contract.name, contract.id)
+
+
+def deactivate_contract(session: Session, contract: EnergyContract) -> None:
+    """Deactivate a contract without touching other contracts.
+
+    Caller must commit after this returns.
+    """
+    contract.active = False
+    contract.updated_at = datetime.now(UTC)
+    logger.info("Deactivated contract %r (id=%d)", contract.name, contract.id)
+
+
+def active_contract_versions(session: Session) -> list[EnergyContractVersion]:
+    """Return all versions of the currently active contract, ordered by effective_from ascending.
+
+    Returns an empty list when there is no active contract.  The list spans the
+    full history of the active contract (all closed + the current open version)
+    and is used to iterate over pricing-rate segments for cross-version fixed-
+    cost / credit accumulation (Principle C).
+    """
+    active = session.execute(
+        select(EnergyContract).where(EnergyContract.active.is_(True)).limit(1)
+    ).scalar_one_or_none()
+
+    if active is None:
+        return []
+
+    return list(
+        session.execute(
+            select(EnergyContractVersion)
+            .where(EnergyContractVersion.contract_id == active.id)
+            .order_by(EnergyContractVersion.effective_from)
+        )
+        .scalars()
+        .all()
+    )
+
+
+def active_contract_version_at(
+    session: Session, ts: datetime
+) -> EnergyContractVersion | None:
+    """Return the active contract's version that covers *ts*.
+
+    A version covers *ts* when:
+        ``effective_from ≤ ts`` AND (``effective_to IS NULL`` OR ``ts < effective_to``)
+
+    Returns None when:
+    - There is no active contract.
+    - The active contract has no version covering *ts*.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session (read-only usage).
+    ts:
+        UTC datetime to look up.
+
+    Returns
+    -------
+    EnergyContractVersion | None
+    """
+    active = session.execute(
+        select(EnergyContract).where(EnergyContract.active.is_(True)).limit(1)
+    ).scalar_one_or_none()
+
+    if active is None:
+        return None
+
+    # Build a query for all versions of the active contract covering ts.
+    stmt = (
+        select(EnergyContractVersion)
+        .where(
+            EnergyContractVersion.contract_id == active.id,
+            EnergyContractVersion.effective_from <= ts,
+        )
+        .order_by(EnergyContractVersion.effective_from.desc())
+        .limit(1)
+    )
+    version = session.execute(stmt).scalar_one_or_none()
+
+    if version is None:
+        return None
+
+    # Exclude versions whose effective window has already closed before ts.
+    if version.effective_to is not None and _as_utc(ts) >= _as_utc(version.effective_to):
+        return None
+
+    return version
@@ -0,0 +1,297 @@
+"""DSMR telegram ingest service.
+
+Subscribes to the DSMR Reader MQTT topic (``dsmr/json``) and persists
+down-sampled DSMR telegram frames to the ``dsmr_reading`` table.
+
+Design decisions
+----------------
+- **Whole-frame storage**: the entire parsed telegram dict is stored as a JSON
+  blob in ``DsmrReading.payload``; no field allow-list is applied.  This lets
+  future commodities (gas, heating, three-phase) be accommodated without a
+  table-schema change.
+- **10-second down-sampling** (configurable via ``dsmr_sample_interval_s``):
+  only telegrams whose ``timestamp`` second falls on an exact multiple of the
+  interval are persisted.  This reduces write volume from ~60 rows/min to ~6
+  rows/min while guaranteeing that every 15-minute boundary (second=00) is
+  captured.
+- **Idempotency**: the telegram's own ``id`` field is stored as ``source_id``
+  with a UNIQUE constraint.  A second delivery of the same telegram (e.g. after
+  a broker reconnect) is silently skipped.
+- **Network-thread safety**: ``handle_message`` is called from paho's background
+  loop thread.  It opens and closes its own short-lived SQLAlchemy session and
+  swallows all exceptions so that a buggy payload or transient DB error never
+  crashes the paho loop or drops the MQTT connection.
+- **Numeric values kept as strings**: the DSMR Reader emits all numeric readings
+  as JSON strings (e.g. ``"20915.154"``).  They are stored verbatim; conversion
+  to ``Decimal`` is deferred to the billing engine (T07) where precision matters.
+- **Null phases**: some telegrams omit certain phase readings (``null`` in JSON);
+  these are stored as-is without special handling.
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+import threading
+from datetime import datetime, timezone
+from typing import TYPE_CHECKING
+
+import sqlalchemy.exc
+from sqlalchemy import select
+
+from app.db import get_session_local
+from app.models.energy import DsmrReading
+
+if TYPE_CHECKING:
+    from app.config import Settings
+
+logger = logging.getLogger(__name__)
+
+
+# Tracks the DSMR topic currently subscribed via the MQTT manager, so a config
+# change can unsubscribe the old topic before subscribing the new one.
+_current_dsmr_topic: str | None = None
+
+# Tracks the DSMR tariff topic currently subscribed via the MQTT manager.
+_current_tariff_topic: str | None = None
+
+# Current electricity tariff: 1 = dal/off-peak, 2 = normal/peak.
+# Written by the paho network thread, read by the publish job — guarded by a lock.
+_current_tariff: int | None = None
+_tariff_lock = threading.Lock()
+
+
+def get_current_tariff() -> int | None:
+    """Return the most recently received electricity tariff (1 or 2), or None."""
+    with _tariff_lock:
+        return _current_tariff
+
+
+def set_current_tariff(value: int | None) -> None:
+    """Set the current electricity tariff (1 or 2), or clear it with None."""
+    with _tariff_lock:
+        global _current_tariff
+        _current_tariff = value
+
+
+def handle_tariff_message(payload_bytes: bytes) -> None:
+    """Parse one DSMR tariff MQTT payload and update the in-memory tariff state.
+
+    Called from the paho network thread; *must* swallow all exceptions so that
+    a bad payload never crashes the loop or drops the broker connection.
+
+    Accepts payload as bytes or str (paho can deliver either).  Ignores
+    whitespace.  Only accepts integer values 1 or 2; anything else is discarded
+    and the previous known tariff is preserved.
+
+    Parameters
+    ----------
+    payload_bytes:
+        Raw bytes from the MQTT message (may also be a str in some paho versions).
+    """
+    try:
+        # Decode bytes → str if needed; strip surrounding whitespace.
+        if isinstance(payload_bytes, (bytes, bytearray)):
+            raw = payload_bytes.decode("utf-8", errors="replace").strip()
+        else:
+            raw = str(payload_bytes).strip()
+
+        value = int(raw)
+        if value not in (1, 2):
+            logger.debug(
+                "dsmr_ingest.handle_tariff_message: unexpected tariff value %d (expected 1 or 2, ignored).",
+                value,
+            )
+            return
+
+        set_current_tariff(value)
+        logger.debug("dsmr_ingest.handle_tariff_message: tariff updated to %d.", value)
+
+    except Exception:
+        # Malformed payload (e.g. non-numeric); swallow silently to protect network thread.
+        logger.debug(
+            "dsmr_ingest.handle_tariff_message: could not parse payload %r (ignored).",
+            payload_bytes,
+        )
+
+
+def apply_dsmr_subscription(settings: "Settings") -> None:
+    """(Re)apply the DSMR MQTT subscriptions to match *settings* — restart-free.
+
+    Call this at startup and after every config save.  It makes the live MQTT
+    subscriptions reflect the current ``dsmr_ingest_enabled`` / ``dsmr_mqtt_topic``
+    / ``dsmr_sample_interval_s`` / ``dsmr_tariff_topic`` settings without an app
+    restart:
+
+    - **Disabled** → unsubscribe any active DSMR and tariff subscriptions.
+    - **Enabled** → (re)subscribe to ``dsmr_mqtt_topic`` with a handler bound to
+      a *fresh* settings snapshot, so a changed sample interval also takes effect.
+      Also subscribe to ``dsmr_tariff_topic`` when non-empty.
+    - **Topic changed** → unsubscribe the old topic before subscribing the new one.
+
+    Idempotent and safe to call when MQTT is not connected (the subscription is
+    queued in the manager and established on the next connect).
+    """
+    # Imported here (not at module top) to avoid a circular import at app start.
+    from app.integrations.mqtt import mqtt_manager
+
+    global _current_dsmr_topic, _current_tariff_topic
+
+    if not settings.dsmr_ingest_enabled:
+        if _current_dsmr_topic is not None:
+            mqtt_manager.unsubscribe(_current_dsmr_topic)
+            logger.info("DSMR ingest disabled — unsubscribed from topic=%s.", _current_dsmr_topic)
+            _current_dsmr_topic = None
+        if _current_tariff_topic is not None:
+            mqtt_manager.unsubscribe(_current_tariff_topic)
+            logger.info(
+                "DSMR ingest disabled — unsubscribed from tariff topic=%s.",
+                _current_tariff_topic,
+            )
+            _current_tariff_topic = None
+        return
+
+    # --- Main DSMR telegram topic ---
+    topic = settings.dsmr_mqtt_topic
+    if _current_dsmr_topic is not None and _current_dsmr_topic != topic:
+        mqtt_manager.unsubscribe(_current_dsmr_topic)
+
+    # Re-subscribe (overwrites any existing handler for this topic) with a fresh
+    # settings snapshot so dsmr_sample_interval_s changes take effect too.
+    snapshot = settings
+    mqtt_manager.subscribe(topic, lambda payload: handle_message(payload, snapshot))
+    _current_dsmr_topic = topic
+    logger.info("DSMR ingest enabled — subscribed to topic=%s.", topic)
+
+    # --- DSMR tariff topic (dual-tariff slot indicator) ---
+    tariff_topic = settings.dsmr_tariff_topic if settings.dsmr_tariff_topic else ""
+    if tariff_topic:
+        if _current_tariff_topic is not None and _current_tariff_topic != tariff_topic:
+            mqtt_manager.unsubscribe(_current_tariff_topic)
+        mqtt_manager.subscribe(tariff_topic, lambda payload: handle_tariff_message(payload))
+        _current_tariff_topic = tariff_topic
+        logger.info("DSMR tariff topic — subscribed to topic=%s.", tariff_topic)
+    else:
+        # tariff_topic is empty → unsubscribe any existing tariff subscription.
+        if _current_tariff_topic is not None:
+            mqtt_manager.unsubscribe(_current_tariff_topic)
+            logger.info(
+                "DSMR tariff topic cleared — unsubscribed from topic=%s.",
+                _current_tariff_topic,
+            )
+            _current_tariff_topic = None
+
+
+def handle_message(payload_bytes: bytes, settings: "Settings") -> None:
+    """Parse one DSMR MQTT payload and persist it if it passes the sample filter.
+
+    Called from the paho network thread; *must* swallow all exceptions so that
+    a bad payload or transient error does not crash the loop or drop the broker
+    connection.
+
+    Parameters
+    ----------
+    payload_bytes:
+        Raw bytes from the MQTT message.
+    settings:
+        Runtime settings snapshot (captured at subscription time).  Used for
+        ``dsmr_sample_interval_s``.
+    """
+    try:
+        _handle_message_inner(payload_bytes, settings)
+    except Exception:
+        logger.exception("dsmr_ingest.handle_message: unexpected error (swallowed).")
+
+
+def _handle_message_inner(payload_bytes: bytes, settings: "Settings") -> None:
+    """Inner implementation — may raise; caller wraps in try/except."""
+    # --- 1. Parse JSON ---
+    try:
+        data: dict = json.loads(payload_bytes)
+    except (json.JSONDecodeError, ValueError):
+        logger.debug("dsmr_ingest: invalid JSON payload (skipped).")
+        return
+
+    if not isinstance(data, dict):
+        logger.debug("dsmr_ingest: payload is not a JSON object (skipped).")
+        return
+
+    # --- 2. Parse timestamp ---
+    raw_ts = data.get("timestamp")
+    if raw_ts is None:
+        logger.debug("dsmr_ingest: missing 'timestamp' field (skipped).")
+        return
+
+    try:
+        # Python 3.11+ accepts the trailing 'Z' directly; for 3.10 compat we
+        # replace 'Z' with '+00:00' before parsing.
+        ts_str = raw_ts if not isinstance(raw_ts, str) else raw_ts.replace("Z", "+00:00")
+        ts_utc: datetime = datetime.fromisoformat(ts_str)
+        # Ensure it is timezone-aware UTC.
+        if ts_utc.tzinfo is None:
+            ts_utc = ts_utc.replace(tzinfo=timezone.utc)
+    except (ValueError, TypeError, AttributeError):
+        logger.debug(
+            "dsmr_ingest: cannot parse 'timestamp' value %r (skipped).", raw_ts
+        )
+        return
+
+    # --- 3. Down-sample: only persist if second falls on interval boundary ---
+    interval = settings.dsmr_sample_interval_s
+    if interval > 0 and (ts_utc.second % interval) != 0:
+        # This telegram is between sample points; discard silently.
+        return
+
+    # --- 4. Extract source_id (telegram's own id) — stored only as a reference,
+    #        NOT used for uniqueness/idempotency (it overflows and gets reset). ---
+    source_id: int | None = data.get("id")
+    if source_id is not None and not isinstance(source_id, int):
+        # Unexpected type — treat as missing rather than raising.
+        logger.debug(
+            "dsmr_ingest: 'id' field has unexpected type %s (ignoring).",
+            type(source_id).__name__,
+        )
+        source_id = None
+
+    # --- 5. Persist to database ---
+    # Idempotency is keyed on recorded_at (the telegram timestamp), which is
+    # telegram-id-independent: a single P1 meter emits one telegram per second,
+    # and down-sampling keeps at most one per interval-aligned second.  The
+    # UNIQUE(recorded_at) constraint is the backstop for the IntegrityError race.
+    session_local = get_session_local()
+    session = session_local()
+    try:
+        existing = session.scalar(
+            select(DsmrReading).where(DsmrReading.recorded_at == ts_utc)
+        )
+        if existing is not None:
+            logger.debug(
+                "dsmr_ingest: recorded_at=%s already in DB, skipping.",
+                ts_utc.isoformat(),
+            )
+            return
+
+        reading = DsmrReading(
+            recorded_at=ts_utc,
+            source_id=source_id,
+            payload=data,  # full frame, verbatim
+        )
+        session.add(reading)
+        session.commit()
+        logger.debug(
+            "dsmr_ingest: persisted reading recorded_at=%s source_id=%s.",
+            ts_utc.isoformat(),
+            source_id,
+        )
+    except sqlalchemy.exc.IntegrityError:
+        # Race / duplicate: another insert beat us to the same recorded_at.
+        session.rollback()
+        logger.debug(
+            "dsmr_ingest: IntegrityError for recorded_at=%s (duplicate, skipped).",
+            ts_utc.isoformat(),
+        )
+    except Exception:
+        session.rollback()
+        logger.exception("dsmr_ingest: DB error (swallowed).")
+    finally:
+        session.close()
@@ -0,0 +1,881 @@
+"""Billing engine for DSMR 15-minute energy metering periods.
+
+This module implements the two-layer billing model described in §3.4 of the
+M6 design document, extended in M7-T03 to be meter-aware:
+
+**Layer 1 — per-period metering cost (immutable, price-snapshot)**
+  ``compute_period(session, t0)`` computes the import cost, export revenue, and
+  net cost for the 15-minute period ``[t0, t0+15min)``.  The result is written
+  to ``energy_cost_period`` with a full pricing snapshot so each row is
+  self-contained and auditable.  Existing *successful* rows are never overwritten
+  by the normal tick path; only an explicit ``recompute_range`` call passes
+  ``overwrite=True``.
+
+**Layer 2 — summary (computed at read time, not stored)**
+  ``summarize(session, start, end)`` aggregates all non-degraded
+  ``energy_cost_period`` rows in ``[start, end)``, then adds the daily
+  standing charges (network_fee + management_fee, apportioned at EUR/month
+  ÷ 30 per day) and subtracts the energy-tax credit (heffingskorting,
+  apportioned at EUR/year ÷ 365 per day).
+
+Design notes
+------------
+- **Decimal arithmetic throughout**: all monetary computations use
+  ``decimal.Decimal`` to avoid float binary rounding errors.  Only when
+  writing to ``EnergyCostPeriod`` columns (Float) are values converted to
+  float.  ``summarize`` converts back to Decimal for summation.
+- **UTC quarter-hour grid**: period boundaries are aligned to UTC 00/15/30/45
+  minutes (``floor_to_quarter``).  NL local time (CET/CEST) is always a whole
+  number of hours from UTC, so the quarter-hour grid is the same in both
+  timezone representations.
+- **Register keys**: DSMR payload uses JSON strings like ``"20915.154"``
+  for cumulative kWh registers.  ``register_at`` converts them to Decimal.
+- **Degraded vs skip semantics**:
+  - *No meter coverage* (``meter_at`` returns None for t0): write a
+    ``degraded=True`` row with ``meter_id=None``.
+  - *Cross-meter boundary* (m0.id != m1.id for t0/t1): write a ``degraded=True``
+    row with ``meter_id=m0.id``; losing this one period at the swap boundary is
+    acceptable (D5 decision).
+  - *Missing readings* (``register_at`` returns None for start or end
+    boundary within the meter window): write a ``degraded=True`` row with
+    ``meter_id=m0.id`` so the period is tracked and can be retried by
+    ``compute_closed_periods``.
+  - *Negative or excessively large delta* (delta sanity guard D6): write a
+    ``degraded=True`` row with ``meter_id=m0.id``; prevents negative costs and
+    grossly inflated costs from meter resets, DSMR rollover, or data spikes.
+  - *Missing Tibber price* (``TibberPriceNotFoundError``): skip entirely (do
+    not write a row); the period will be retried once prices arrive.
+  - *Missing active contract version*: skip (no contract to compute against).
+- **Meter-aware register lookup**: ``register_at`` now accepts a ``meter``
+  parameter and restricts the DSMR reading query to readings within
+  ``[meter.started_at, meter.ended_at)`` (half-open), preventing old-meter
+  readings from leaking into a new-meter epoch.
+- **Lookback window in ``compute_closed_periods``**: to avoid scanning all
+  historical DSMR data on every tick, the function looks back at most 7 days
+  from the current time.  This covers typical short outages (no data / no
+  contract) while staying bounded.  Periods older than 7 days must be
+  recovered via an explicit ``recompute_range`` call.
+
+Meter-aware compute_period ordering rationale (M7-T03)
+-------------------------------------------------------
+The order of checks inside ``compute_period`` is:
+
+1. **Immutability guard** (existing non-degraded row, overwrite=False) → return False.
+2. **Meter determination** (m0 = meter_at(t0), m1 = meter_at(t1)):
+   - No meter (m0 is None) → write degraded, meter_id=None.
+   - Cross-meter boundary (m0.id != m1.id) → write degraded, meter_id=m0.id.
+3. **Active contract version check** → skip (no write) if absent.
+4. **Boundary register readings** within m0's window → write degraded if missing.
+5. **Delta sanity guard** → write degraded if any delta < 0 or > _MAX_DELTA_KWH.
+6. **Price strategy** → skip (no write) if Tibber price missing.
+7. **Upsert billing record** with meter_id=m0.id.
+
+Why meter before contract? The meter is a *structural* prerequisite: without a
+known meter epoch we cannot trust the delta at all, so we commit a degraded row
+immediately.  The contract skip, by contrast, is transient (the period can be
+re-computed once a contract is configured), so it produces no row.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime, timedelta
+from decimal import Decimal
+from typing import Any
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.integrations.pricing.strategies import (
+    PeriodDeltas,
+    TibberPriceNotFoundError,
+    get_strategy,
+)
+from app.models.energy import DsmrReading, EnergyCostPeriod, Meter
+from app.services.contracts import active_contract_version_at, active_contract_versions
+from app.services.meters import meter_at
+from app.services.timezone import local_date, local_now
+
+logger = logging.getLogger(__name__)
+
+# ---------------------------------------------------------------------------
+# Constants
+# ---------------------------------------------------------------------------
+
+_PERIOD_MINUTES = 15
+_LOOKBACK_DAYS = 7  # maximum lookback window for compute_closed_periods
+
+# Maximum age a DSMR reading may have relative to the boundary being queried.
+# Under normal operation DSMR readings arrive every ~10 seconds, so a reading
+# more than one period (15 minutes) old at the boundary indicates either a data
+# gap or — critically — a *future* boundary being resolved against the last
+# historical reading.  In both cases the reading is considered stale and
+# ``register_at`` returns None, letting the period be marked degraded instead of
+# producing a spurious zero-delta "successful" row.
+_READING_MAX_STALENESS = timedelta(minutes=_PERIOD_MINUTES)
+
+# Maximum plausible kWh delta for a single 15-minute period (D6 sanity guard).
+# A typical Dutch household uses well under 5 kWh per quarter hour even under
+# heavy load.  100 kWh per 15 minutes corresponds to ~400 kW — far beyond any
+# residential consumption — but is lenient enough to never fire on legitimate
+# data.  Any delta at or above this threshold indicates a meter reset, DSMR
+# rollover, sign error, or other data anomaly, and the period is marked
+# degraded to prevent negative costs or grossly inflated charges.
+_MAX_DELTA_KWH = Decimal("100")
+
+# DSMR payload register keys (cumulative kWh, JSON string values).
+_KEY_D1 = "electricity_delivered_1"   # delivered low-tariff  (dal / _1)
+_KEY_D2 = "electricity_delivered_2"   # delivered high-tariff (normal / _2)
+_KEY_R1 = "electricity_returned_1"    # returned  low-tariff
+_KEY_R2 = "electricity_returned_2"    # returned  high-tariff
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def floor_to_quarter(dt: datetime) -> datetime:
+    """Return *dt* floored to the nearest UTC quarter-hour boundary.
+
+    The result always has seconds=0 and microseconds=0, and minutes in
+    {0, 15, 30, 45}.  Timezone info is preserved if present.
+    """
+    floored_minute = (dt.minute // _PERIOD_MINUTES) * _PERIOD_MINUTES
+    return dt.replace(minute=floored_minute, second=0, microsecond=0)
+
+
+def _to_decimal(value: Any) -> Decimal:
+    """Convert *value* to Decimal via str() to avoid float binary rounding."""
+    return Decimal(str(value))
+
+
+def _as_utc(dt: datetime) -> datetime:
+    """Attach UTC tzinfo to a naive datetime (SQLite read-back workaround)."""
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=UTC)
+    return dt
+
+
+def _existing_period(session: Session, t0: datetime) -> EnergyCostPeriod | None:
+    """Return the EnergyCostPeriod row for period_start=t0, or None."""
+    return session.execute(
+        select(EnergyCostPeriod).where(EnergyCostPeriod.period_start == t0)
+    ).scalar_one_or_none()
+
+
+# ---------------------------------------------------------------------------
+# register_at — boundary reading lookup (meter-aware)
+# ---------------------------------------------------------------------------
+
+
+def register_at(
+    session: Session,
+    boundary: datetime,
+    meter: Meter,
+) -> dict[str, Decimal] | None:
+    """Return the four cumulative kWh register values at *boundary*, within *meter*'s window.
+
+    Queries the most recent ``DsmrReading`` with:
+        ``recorded_at ≤ boundary``
+        AND ``recorded_at ≥ meter.started_at``
+        AND (``meter.ended_at IS NULL`` OR ``recorded_at < meter.ended_at``)
+
+    The meter window constraint (half-open ``[started_at, ended_at)``) ensures
+    that readings from a previous meter epoch are never used to anchor a new
+    meter's computation.  Without this guard, the final reading of the old meter
+    would be visible at the start of the new meter's epoch and produce a
+    cross-meter delta, defeating the isolation guarantee.
+
+    Extracts the four energy registers from ``payload``:
+
+        d1 — electricity_delivered_1  (delivered low-tariff / dal)
+        d2 — electricity_delivered_2  (delivered high-tariff / normal)
+        r1 — electricity_returned_1   (returned  low-tariff)
+        r2 — electricity_returned_2   (returned  high-tariff)
+
+    Returns
+    -------
+    dict[str, Decimal] with keys ``d1``, ``d2``, ``r1``, ``r2``, or ``None``
+    when:
+    - No ``DsmrReading`` row exists with ``recorded_at ≤ boundary`` within
+      *meter*'s epoch window.
+    - The most recent such reading is older than ``_READING_MAX_STALENESS``
+      relative to *boundary* (freshness guard).
+    - Any of the four register keys is absent from the payload.
+    - Any of the four register values is ``None`` (null in JSON).
+
+    SQLite naive datetime note
+    --------------------------
+    ``recorded_at`` is stored as a naive UTC datetime in SQLite.  Comparisons
+    against *boundary* (always tz-aware UTC) use ``_as_utc()`` for the
+    freshness check.  The SQL ``WHERE`` clause comparisons work correctly
+    because SQLAlchemy's SQLite dialect strips tzinfo when binding parameters
+    (leaving the wall-clock UTC value unchanged), consistent with the storage
+    format.
+    """
+    # Build the meter-window constraints: [started_at, ended_at).
+    meter_lower = meter.started_at  # DsmrReading.recorded_at >= meter.started_at
+    meter_upper = meter.ended_at    # DsmrReading.recorded_at < meter.ended_at (if set)
+
+    stmt = (
+        select(DsmrReading)
+        .where(
+            DsmrReading.recorded_at <= boundary,
+            DsmrReading.recorded_at >= meter_lower,
+        )
+        .order_by(DsmrReading.recorded_at.desc())
+        .limit(1)
+    )
+    # Apply the upper bound only when the meter is closed (ended_at is not None).
+    if meter_upper is not None:
+        stmt = stmt.where(DsmrReading.recorded_at < meter_upper)
+
+    row: DsmrReading | None = session.execute(stmt).scalar_one_or_none()
+
+    if row is None:
+        return None
+
+    # Freshness guard: reject readings that are too old relative to *boundary*.
+    # ``recorded_at`` is stored as a naive UTC datetime in SQLite; attach UTC
+    # tzinfo before comparing with *boundary* (which is always tz-aware UTC) to
+    # avoid an "offset-naive vs offset-aware" TypeError.
+    if _as_utc(row.recorded_at) < _as_utc(boundary) - _READING_MAX_STALENESS:
+        return None
+
+    payload = row.payload or {}
+    try:
+        d1_raw = payload[_KEY_D1]
+        d2_raw = payload[_KEY_D2]
+        r1_raw = payload[_KEY_R1]
+        r2_raw = payload[_KEY_R2]
+    except KeyError:
+        return None
+
+    if any(v is None for v in (d1_raw, d2_raw, r1_raw, r2_raw)):
+        return None
+
+    return {
+        "d1": _to_decimal(d1_raw),
+        "d2": _to_decimal(d2_raw),
+        "r1": _to_decimal(r1_raw),
+        "r2": _to_decimal(r2_raw),
+    }
+
+
+# ---------------------------------------------------------------------------
+# compute_period — single 15-minute period
+# ---------------------------------------------------------------------------
+
+
+def compute_period(session: Session, t0: datetime, *, overwrite: bool = False) -> bool:
+    """Compute and upsert the billing record for the period ``[t0, t0+15min)``.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  Caller is responsible for committing.
+    t0:
+        UTC start of the 15-minute period.  **Must** lie on a quarter-hour
+        grid boundary (minutes ∈ {0, 15, 30, 45}, seconds=0, microseconds=0).
+    overwrite:
+        If ``True``, overwrite an existing *successful* row (i.e. re-compute
+        even when a non-degraded record already exists).  The normal tick path
+        always passes ``False``; only ``recompute_range`` passes ``True``.
+
+    Returns
+    -------
+    bool
+        ``True`` if a record was written (inserted or updated), ``False`` if
+        the period was skipped (missing contract or missing Tibber price).
+
+    Side-effects
+    ------------
+    - Inserts or updates an ``EnergyCostPeriod`` row keyed on ``period_start=t0``.
+    - If no meter covers t0 (``meter_at`` returns None for t0): inserts/updates
+      a degraded row with ``meter_id=None``.
+    - If the period spans a meter boundary (``meter_at(t0).id != meter_at(t1).id``):
+      inserts/updates a degraded row with ``meter_id=m0.id`` (D5 decision).
+    - If readings are missing at either boundary within the meter window:
+      inserts/updates a degraded row with ``meter_id=m0.id``.
+    - If any delta is negative or exceeds ``_MAX_DELTA_KWH`` (D6 sanity guard):
+      inserts/updates a degraded row with ``meter_id=m0.id``.
+    - If the active contract version is missing: **skips** (returns False, no write).
+    - If the Tibber price is missing (TibberPriceNotFoundError): **skips**
+      (returns False, no write).
+    """
+    t1 = t0 + timedelta(minutes=_PERIOD_MINUTES)
+    now = datetime.now(UTC)
+
+    # Immutability guard: skip if a successful record already exists and we
+    # are not in overwrite mode.
+    existing = _existing_period(session, t0)
+    if existing is not None and not existing.degraded and not overwrite:
+        return False
+
+    # --- Meter determination (structural prerequisite, checked before contract) ---
+    #
+    # A missing or cross-boundary meter is a structural problem: we cannot trust
+    # the delta at all, so we write a degraded row immediately.  This is different
+    # from the contract skip (transient, no write): the degraded row ensures the
+    # period appears in the history and can be revisited once the meter timeline
+    # is corrected and a recompute_range is triggered.
+    #
+    # Ordering rationale:
+    #   1. No meter (m0 is None) → degraded(meter_id=None): no epoch for t0.
+    #   2. Cross-meter boundary (m0.id != m1.id) → degraded(meter_id=m0.id): D5.
+    #   3. (Single meter, proceed) → contract check → readings → delta guard → price.
+    #
+    # We place meter before contract so that "cross-table period" is always
+    # marked degraded regardless of contract state.  If we checked contract
+    # first, a missing-contract skip would silently discard the cross-table
+    # evidence; once a contract is added and recompute runs, the engine would
+    # incorrectly use cross-table reads.
+    m0 = meter_at(session, t0)
+    m1 = meter_at(session, t1)
+
+    if m0 is None:
+        # No meter epoch covers t0 — degraded with no meter attribution.
+        logger.debug(
+            "compute_period(%s): no active meter at t0 — writing degraded (meter_id=None).",
+            t0.isoformat(),
+        )
+        _upsert_degraded(session, t0, now, existing, meter_id=None)
+        return True
+
+    if m1 is None or m0.id != m1.id:
+        # Period spans a meter boundary or t1 has no meter.  Degrade with m0's id
+        # (t0's meter attribution): the period's start belongs to m0's epoch.
+        logger.debug(
+            "compute_period(%s): period crosses meter boundary "
+            "(m0.id=%s, m1.id=%s) — writing degraded.",
+            t0.isoformat(),
+            m0.id,
+            m1.id if m1 is not None else None,
+        )
+        _upsert_degraded(session, t0, now, existing, meter_id=m0.id)
+        return True
+
+    # --- Active contract version at t0 ---
+    # If there is no active contract covering t0, skip the period entirely.
+    # We do not write a degraded row — there is no meaningful state to recover
+    # without a contract (we would not know which strategy to apply once data
+    # arrives). The period can be recovered via an explicit recompute_range once
+    # a contract is configured and activated.
+    version = active_contract_version_at(session, t0)
+    if version is None:
+        logger.debug("compute_period(%s): no active contract version — skipping.", t0.isoformat())
+        return False
+
+    # --- Boundary readings within m0's meter window ---
+    start_regs = register_at(session, t0, m0)
+    end_regs = register_at(session, t1, m0)
+
+    if start_regs is None or end_regs is None:
+        # Missing readings within the meter window → degraded with m0 attribution.
+        _upsert_degraded(session, t0, now, existing, meter_id=m0.id)
+        return True  # a record was written (degraded)
+
+    # --- Compute deltas (end − start) ---
+    deltas = PeriodDeltas(
+        d1=end_regs["d1"] - start_regs["d1"],
+        d2=end_regs["d2"] - start_regs["d2"],
+        r1=end_regs["r1"] - start_regs["r1"],
+        r2=end_regs["r2"] - start_regs["r2"],
+    )
+
+    # --- Delta sanity guard (D6) ---
+    # Any negative delta indicates a meter reset, DSMR rollover, or data error.
+    # Any delta exceeding _MAX_DELTA_KWH (100 kWh per 15 min = 400 kW average)
+    # is implausible for residential use and indicates an anomaly.
+    # Both cases produce a degraded row so no negative or grossly inflated cost
+    # is ever written to the billing record.
+    all_deltas = (deltas.d1, deltas.d2, deltas.r1, deltas.r2)
+    if any(d < Decimal("0") for d in all_deltas) or any(d > _MAX_DELTA_KWH for d in all_deltas):
+        logger.debug(
+            "compute_period(%s): delta sanity guard triggered "
+            "(d1=%s, d2=%s, r1=%s, r2=%s) — writing degraded.",
+            t0.isoformat(),
+            deltas.d1,
+            deltas.d2,
+            deltas.r1,
+            deltas.r2,
+        )
+        _upsert_degraded(session, t0, now, existing, meter_id=m0.id)
+        return True
+
+    # --- Price strategy ---
+    strategy = get_strategy(version.contract.kind)
+    try:
+        result = strategy(deltas, t0, version.values, session)
+    except TibberPriceNotFoundError:
+        # Missing Tibber price → skip the period; it will be retried once the
+        # price arrives (e.g. after the next Tibber refresh job runs).
+        logger.debug(
+            "compute_period(%s): no Tibber price found — skipping.", t0.isoformat()
+        )
+        return False
+
+    # --- Upsert the billing record ---
+    import_cost: Decimal = result["import_cost"]
+    export_revenue: Decimal = result["export_revenue"]
+    net_cost: Decimal = result["net_cost"]
+    pricing: dict = result["pricing"]
+
+    if existing is not None:
+        # Update in-place (overwrite=True or previous record was degraded).
+        existing.d1_kwh = float(deltas.d1)
+        existing.d2_kwh = float(deltas.d2)
+        existing.r1_kwh = float(deltas.r1)
+        existing.r2_kwh = float(deltas.r2)
+        existing.import_cost = float(import_cost)
+        existing.export_revenue = float(export_revenue)
+        existing.net_cost = float(net_cost)
+        existing.currency = version.contract.currency
+        existing.pricing = pricing
+        existing.contract_version_id = version.id
+        existing.meter_id = m0.id
+        existing.degraded = False
+        existing.computed_at = now
+    else:
+        period = EnergyCostPeriod(
+            period_start=t0,
+            d1_kwh=float(deltas.d1),
+            d2_kwh=float(deltas.d2),
+            r1_kwh=float(deltas.r1),
+            r2_kwh=float(deltas.r2),
+            import_cost=float(import_cost),
+            export_revenue=float(export_revenue),
+            net_cost=float(net_cost),
+            currency=version.contract.currency,
+            pricing=pricing,
+            contract_version_id=version.id,
+            meter_id=m0.id,
+            degraded=False,
+            computed_at=now,
+        )
+        session.add(period)
+
+    return True
+
+
+def _upsert_degraded(
+    session: Session,
+    t0: datetime,
+    now: datetime,
+    existing: EnergyCostPeriod | None,
+    *,
+    meter_id: int | None,
+) -> None:
+    """Insert or update a degraded placeholder for period *t0*.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.
+    t0:
+        UTC start of the 15-minute period.
+    now:
+        Current UTC timestamp for the ``computed_at`` field.
+    existing:
+        The existing ``EnergyCostPeriod`` row for this period, or ``None``.
+    meter_id:
+        The meter ID to attribute this degraded period to, or ``None`` when
+        no meter epoch covers the period (no-meter degraded case).
+
+    When *existing* is not None (row was previously written — either degraded
+    or successful), the row is explicitly reset to the standard degraded state.
+    This is required for the ``recompute_range`` (overwrite=True) path: if the
+    row was previously a *successful* computation and the boundary readings have
+    since disappeared, the stale non-zero costs must be cleared so the row
+    accurately reflects the current "missing readings" state rather than
+    masquerading as a valid result.
+
+    The ``meter_id`` is always updated to reflect the current meter attribution
+    judgment (the result of ``meter_at`` at the time of recompute).  This
+    ensures that a retroactive ``started_at`` change + ``recompute_range`` will
+    re-attribute historical degraded periods to the correct meter epoch.
+    """
+    if existing is not None:
+        # Explicitly reset to degraded state — identical field values to the
+        # new-row path below.  This covers the recompute-over-successful-row
+        # case where old non-zero costs must not survive the downgrade.
+        existing.d1_kwh = 0.0
+        existing.d2_kwh = 0.0
+        existing.r1_kwh = 0.0
+        existing.r2_kwh = 0.0
+        existing.import_cost = 0.0
+        existing.export_revenue = 0.0
+        existing.net_cost = 0.0
+        existing.pricing = {}
+        existing.contract_version_id = None
+        existing.meter_id = meter_id
+        existing.degraded = True
+        existing.computed_at = now
+    else:
+        period = EnergyCostPeriod(
+            period_start=t0,
+            d1_kwh=0.0,
+            d2_kwh=0.0,
+            r1_kwh=0.0,
+            r2_kwh=0.0,
+            import_cost=0.0,
+            export_revenue=0.0,
+            net_cost=0.0,
+            currency="EUR",  # placeholder; real currency known after contract lookup
+            pricing={},
+            contract_version_id=None,
+            meter_id=meter_id,
+            degraded=True,
+            computed_at=now,
+        )
+        session.add(period)
+
+
+# ---------------------------------------------------------------------------
+# compute_closed_periods — periodic tick
+# ---------------------------------------------------------------------------
+
+
+def compute_closed_periods(session: Session) -> int:
+    """Find and compute all uncalculated closed 15-minute periods.
+
+    A period ``[t0, t1)`` is *closed* when ``t1 ≤ now``.  This function:
+
+    1. Determines the lookback window: from ``now − LOOKBACK_DAYS`` to ``now``,
+       floored to the nearest quarter-hour.  This avoids an unbounded full
+       historical scan on every tick while still covering the typical recovery
+       window (short outages, missing contract, etc.).  Periods older than
+       ``LOOKBACK_DAYS`` must be recovered via an explicit ``recompute_range``.
+    2. Iterates over all quarter-hour boundaries in that window where
+       ``t1 ≤ now`` (i.e. the period has already closed).
+    3. For each boundary, calls ``compute_period(overwrite=False)``, which:
+       - Skips periods that already have a *successful* (non-degraded) record.
+       - Retries periods that have a *degraded* record.
+       - Writes degraded rows for periods with no meter or cross-meter boundaries.
+       - Skips periods for which no active contract version exists or the
+         Tibber price is unavailable (without writing a degraded row).
+
+    Returns
+    -------
+    int
+        Number of periods for which a record was written (inserted or updated).
+        Does not count skipped periods.
+    """
+    now = datetime.now(UTC)
+    # Current period boundary (the one whose t1 has not yet passed).
+    current_t0 = floor_to_quarter(now)
+    # Earliest boundary to consider.
+    earliest_t0 = floor_to_quarter(now - timedelta(days=_LOOKBACK_DAYS))
+
+    written = 0
+    t0 = earliest_t0
+    while t0 < current_t0:
+        t1 = t0 + timedelta(minutes=_PERIOD_MINUTES)
+        if t1 <= now:
+            try:
+                did_write = compute_period(session, t0, overwrite=False)
+                if did_write:
+                    written += 1
+            except Exception:
+                logger.exception(
+                    "compute_closed_periods: unexpected error for t0=%s — continuing.",
+                    t0.isoformat(),
+                )
+        t0 += timedelta(minutes=_PERIOD_MINUTES)
+
+    if written:
+        session.commit()
+        logger.info("compute_closed_periods: wrote %d period(s).", written)
+    return written
+
+
+# ---------------------------------------------------------------------------
+# recompute_range — explicit full recompute
+# ---------------------------------------------------------------------------
+
+
+def recompute_range(session: Session, start: datetime, end: datetime) -> int:
+    """Recompute (overwrite) all 15-minute periods in ``[start, end)``.
+
+    This is the *explicit opt-in* path for recovering from:
+    - Periods where readings or prices arrived late.
+    - Price corrections (new contract version retroactively applied).
+    - Retroactive meter changes (``update_meter`` with new ``started_at``) —
+      re-running this function will re-judge meter attribution and re-compute
+      costs using the corrected epoch boundaries.
+    - Any other reason to override the immutability guard.
+
+    The function iterates over every UTC quarter-hour boundary in
+    ``[floor(start), end)`` and calls ``compute_period(overwrite=True)``.
+    Existing rows (including successful ones) are overwritten; their
+    ``meter_id`` fields will reflect the *current* ``meter_at`` judgment for
+    each period's start timestamp, naturally re-attributing periods when meter
+    ``started_at`` values have been retroactively corrected.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  The function commits after all periods
+        have been processed.
+    start:
+        Inclusive start datetime (floored to the nearest quarter-hour internally).
+    end:
+        Exclusive end datetime.
+
+    Returns
+    -------
+    int
+        Number of periods for which a record was written (inserted or updated).
+        Periods skipped due to missing contract or missing Tibber price are
+        *not* counted.
+    """
+    t0 = floor_to_quarter(_as_utc(start))
+    end_utc = _as_utc(end)
+    now = datetime.now(UTC)
+
+    written = 0
+    while t0 < end_utc:
+        t1 = t0 + timedelta(minutes=_PERIOD_MINUTES)
+        # Only recompute periods that have already closed (t1 ≤ now).  Even
+        # when the caller passes a future *end*, we must not write speculative
+        # "future" rows: register_at would resolve to the latest historical
+        # reading for both boundaries, producing a zero-delta fake-success row
+        # that blocks the real computation once the period actually closes.
+        if t1 <= now:
+            try:
+                did_write = compute_period(session, t0, overwrite=True)
+                if did_write:
+                    written += 1
+            except Exception:
+                logger.exception(
+                    "recompute_range: unexpected error for t0=%s — continuing.",
+                    t0.isoformat(),
+                )
+        t0 += timedelta(minutes=_PERIOD_MINUTES)
+
+    session.commit()
+    logger.info(
+        "recompute_range(%s, %s): wrote %d period(s).",
+        start.isoformat(),
+        end.isoformat(),
+        written,
+    )
+    return written
+
+
+# ---------------------------------------------------------------------------
+# summarize — layer-2 aggregation (read-time, not stored)
+# ---------------------------------------------------------------------------
+
+
+def summarize(session: Session, start: datetime, end: datetime) -> dict[str, Any]:
+    """Aggregate billing for the interval ``[start, end)``.
+
+    Computes the total payable as:
+
+        total_payable = Σ(net_cost)              -- metered electricity
+                      + fixed_costs              -- per-day standing charges, cross-version
+                      - credits                  -- per-day heffingskorting, cross-version
+
+    **Fixed-cost / credit counting — Principle C (symmetric begin/end)**:
+    Both the local calendar day in which *start* falls and the local calendar
+    day in which *end* falls are counted as full days.  Fixed charges
+    (network_fee, management_fee) and the energy-tax credit (heffingskorting)
+    are assessed on a "service-is-active" basis — if the meter was online on a
+    given calendar day, the full day's charge/credit applies, regardless of
+    whether the window starts at midnight or mid-morning.
+
+    For each local calendar date D in the range
+    ``[local_date(start), min(local_date(end), today_local)]``:
+    - D ≤ today_local (only elapsed / today days count as "whole days").
+    - The contract version whose effective_from local-date ≤ D is used.
+    - This is cross-version: if V1 is from June 1 and V2 from June 25,
+      querying June 1–30 uses V1 for days 1-24 and V2 for day 25.
+
+    The end-day (last_counted) is included when the end's local midnight falls
+    strictly before end_utc; combined with the always-counted start day this
+    makes the begin/end handling symmetric.  A short same-day window therefore
+    counts its single local day.  A window contributes 0 days only when the
+    counted range is empty (first_counted > last_counted) — e.g. a window lying
+    entirely in the future, since last_counted is capped at today_local.
+
+    Daily getters (``*_today``) use windows exactly aligned to local midnight,
+    so their ``first_counted`` is always today — unaffected by this fix.
+
+    Days that have not yet started in local time (D > today_local) are
+    never counted.  Switching versions never resets the counter.
+
+    **Timezone note**: the ``days`` field in the returned dict still represents
+    the window length in calendar days (total_seconds / 86400), for backward
+    compatibility with existing API consumers.  The fixed/credit calculation
+    independently counts whole local days as described above.
+
+    All arithmetic uses Decimal; the returned dict contains Python floats for
+    JSON-serialisation convenience.
+
+    Parameters
+    ----------
+    session:
+        Active read-only SQLAlchemy session.
+    start:
+        Inclusive start of the summary interval (UTC or naive-UTC).
+    end:
+        Exclusive end of the summary interval (UTC or naive-UTC).
+
+    Returns
+    -------
+    dict with keys:
+
+        currency          str    ISO 4217 currency (from contract, or "EUR" fallback)
+        metered_import    float  Σ import_cost from non-degraded periods
+        metered_export    float  Σ export_revenue from non-degraded periods
+        metered_net       float  Σ net_cost from non-degraded periods
+        fixed_costs       float  standing charges for elapsed whole local days
+        credits           float  energy-tax credit for elapsed whole local days
+        total_payable     float  metered_net + fixed_costs − credits
+        period_count      int    number of non-degraded periods in range
+        degraded_count    int    number of degraded periods in range
+        days              float  interval length in days (total_seconds / 86400)
+    """
+    from datetime import timedelta as _td, date as _date
+
+    start_utc = _as_utc(start)
+    end_utc = _as_utc(end)
+
+    # --- Fetch all EnergyCostPeriod rows in [start, end) ---
+    rows = session.execute(
+        select(EnergyCostPeriod).where(
+            EnergyCostPeriod.period_start >= start_utc,
+            EnergyCostPeriod.period_start < end_utc,
+        )
+    ).scalars().all()
+
+    good_rows = [r for r in rows if not r.degraded]
+    degraded_rows = [r for r in rows if r.degraded]
+
+    # Σ monetary amounts (Decimal arithmetic).
+    sum_import = sum((_to_decimal(r.import_cost) for r in good_rows), Decimal("0"))
+    sum_export = sum((_to_decimal(r.export_revenue) for r in good_rows), Decimal("0"))
+    sum_net = sum((_to_decimal(r.net_cost) for r in good_rows), Decimal("0"))
+
+    # --- Interval length in days (window, not elapsed — kept for API compat) ---
+    total_seconds = (end_utc - start_utc).total_seconds()
+    days = _to_decimal(str(total_seconds)) / _to_decimal("86400")
+
+    # --- Fixed costs and credits: Principle C cross-version whole-day counting ---
+    today_local: _date = local_now().date()
+
+    # --- Compute [first_counted, last_counted] local date range (inclusive) ---
+    #
+    # Both the window-start day and the window-end day are counted as complete
+    # local calendar days, regardless of whether the window starts/ends at midnight.
+    #
+    # Principle C (symmetric begin/end):
+    #   • first_counted = local calendar date of start_utc  (start day always counted)
+    #   • last_counted  = local calendar date of end_utc    (end day counted if its
+    #                     local midnight is strictly before end_utc)
+    #   • Both are then capped at today_local (only elapsed / today days count).
+    #
+    # Why symmetric? Fixed charges (network_fee, management_fee) and energy-tax credits
+    # (heffingskorting) are assessed on a "service-is-active" basis, not on how many
+    # hours the service was actually running within that calendar day.  If the meter
+    # anchor (started_at) falls at 09:18 on June 24, the full June 24 standing charge
+    # and credit still apply because the service was online for that day.
+    #
+    # Previous asymmetric behaviour: a start_utc that was *later* than the local
+    # midnight of local_start_date caused first_counted to be bumped to the *next*
+    # day, silently dropping the anchor day's charges/credits.  This was incorrect
+    # for cumulative entities (import_cost_total / export_revenue_total) whose anchor
+    # is often an above-midnight started_at.  The end-side had always been symmetric
+    # (counted if local midnight < end_utc), creating an inconsistency.
+    #
+    # Daily getters (window = [local today 00:00, local tomorrow 00:00)) are
+    # unaffected: local_date(local_midnight_utc(today)) == today, so first_counted
+    # is still today regardless of the fix.
+    #
+    # A short same-day window now counts its single local day (the start day is
+    # always counted, symmetric with the end side).  A window contributes 0 days
+    # only when the counted range is empty (first_counted > last_counted) — e.g. a
+    # window lying entirely in the future, where last_counted is capped at
+    # today_local while first_counted is later.
+    from app.services.timezone import local_midnight_utc as _lmu
+
+    # Start side: always count the local calendar day in which start_utc falls.
+    first_counted: _date = local_date(start_utc)
+
+    local_end_date: _date = local_date(end_utc)
+    # Is the midnight of local_end_date < end_utc?  If yes, that day's midnight is in range.
+    if _lmu(local_end_date) < end_utc:
+        last_counted: _date = local_end_date
+    else:
+        last_counted = local_end_date - _td(days=1)
+
+    # Cap: only elapsed or today's days.
+    last_counted = min(last_counted, today_local)
+
+    # If the range is empty (first_counted > last_counted), no days are counted.
+
+    # Fetch all versions of the active contract once (single DB call).
+    versions = active_contract_versions(session)
+
+    fixed_dec = Decimal("0")
+    credits_dec = Decimal("0")
+    currency = "EUR"
+
+    if versions:
+        # Currency comes from the contract regardless of day count.
+        currency = versions[0].contract.currency
+
+    if versions and first_counted <= last_counted:
+        # For each version segment, find its overlap with [first_counted, last_counted]
+        # and accumulate whole days.
+        version_segments: list[tuple[_date, _date | None, dict]] = []
+        for v in versions:
+            v_start_local = local_date(_as_utc(v.effective_from))
+            v_end_local = local_date(_as_utc(v.effective_to)) if v.effective_to is not None else None
+            version_segments.append((v_start_local, v_end_local, v.values or {}))
+
+        for v_start, v_end_excl, v_values in version_segments:
+            # The version covers [v_start, v_end_excl) in local dates,
+            # where v_end_excl=None means open-ended (no upper bound).
+            # Intersection with [first_counted, last_counted]:
+            seg_start = max(first_counted, v_start)
+            if v_end_excl is not None:
+                seg_end_excl = min(last_counted + _td(days=1), v_end_excl)
+            else:
+                seg_end_excl = last_counted + _td(days=1)
+
+            if seg_start >= seg_end_excl:
+                continue  # no overlap
+
+            n_days = (seg_end_excl - seg_start).days
+            if n_days <= 0:
+                continue
+
+            standing: dict = v_values.get("standing", {})
+            creds: dict = v_values.get("credits", {})
+
+            network_fee = _to_decimal(standing.get("network_fee", 0))
+            management_fee = _to_decimal(standing.get("management_fee", 0))
+            heffingskorting = _to_decimal(creds.get("heffingskorting", 0))
+
+            # Standing charges: EUR/month → EUR/day (÷ 30) × n_days.
+            fixed_dec += (network_fee + management_fee) / Decimal("30") * Decimal(str(n_days))
+            # Energy-tax credit: EUR/year → EUR/day (÷ 365) × n_days.
+            credits_dec += heffingskorting / Decimal("365") * Decimal(str(n_days))
+
+    total_payable = sum_net + fixed_dec - credits_dec
+
+    return {
+        "currency": currency,
+        "metered_import": float(sum_import),
+        "metered_export": float(sum_export),
+        "metered_net": float(sum_net),
+        "fixed_costs": float(fixed_dec),
+        "credits": float(credits_dec),
+        "total_payable": float(total_payable),
+        "period_count": len(good_rows),
+        "degraded_count": len(degraded_rows),
+        "days": float(days),
+    }
@@ -0,0 +1,499 @@
+"""HA MQTT Discovery service — build and publish discovery configs + state.
+
+This module handles:
+
+1. Building HA MQTT Discovery payloads for each ``ExposableEntity``.
+2. Publishing discovery configs (retained) for enabled entities.
+3. Clearing (empty-payload) discovery configs for disabled entities.
+4. Publishing current entity state values.
+5. A per-device helper for use in the Modbus poll loop.
+
+Design
+------
+- **No-op when MQTT / discovery is not configured**: every public function
+  checks ``ha_discovery_enabled`` and ``mqtt_manager.is_connected`` before
+  doing any work.  Callers never need to guard these conditions.
+- **Stable unique_id**: derived from device ``uuid`` + metric ``key``, never
+  from mutable fields like ``friendly_name`` or auto-increment DB ids.
+- **Discovery topic format**: ``<discovery_prefix>/<component>/<node_id>/<object_id>/config``
+  where ``node_id`` is the device uuid (slugified to be safe) and
+  ``object_id`` is a uuid-prefixed stable string.  Uses ``ha_discovery_prefix``
+  (default ``"homeassistant"``), which must stay under the HA discovery namespace.
+- **State topic format**: ``<state_prefix>/<component>/<node_id>/<object_id>/state``
+  Uses ``ha_state_topic_prefix`` (default ``"home_automation"``), separate from
+  the discovery namespace so HA discovery and state/availability topics live under
+  different prefixes.
+- **Availability topic**: ``<state_prefix>/modbus/<node_id>/availability`` (shared
+  across all entities of the same device; publishes "online"/"offline").  Also uses
+  the state prefix, not the discovery prefix.
+- **best-effort**: functions catch all exceptions internally so that callers
+  (e.g. the Modbus poll loop) never crash due to MQTT publish errors.
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+from typing import Any
+
+from sqlalchemy.orm import Session
+
+from app.integrations.expose import ExposableEntity, build_catalog
+from app.integrations.mqtt import mqtt_manager
+from app.services.config_page import build_runtime_settings
+
+logger = logging.getLogger(__name__)
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _should_publish(settings: Any) -> bool:
+    """Return True only if MQTT and HA Discovery are both enabled and connected."""
+    return bool(
+        settings.mqtt_enabled
+        and settings.ha_discovery_enabled
+        and mqtt_manager.is_connected
+    )
+
+
+def _node_id(device_uuid: str) -> str:
+    """Stable MQTT node_id derived from device uuid (replace hyphens for safety)."""
+    return device_uuid.replace("-", "_")
+
+
+def _object_id(entity: ExposableEntity) -> str:
+    """Stable MQTT object_id derived from entity key (dots + hyphens → underscores)."""
+    return entity.key.replace(".", "_").replace("-", "_")
+
+
+def _discovery_topic(entity: ExposableEntity, prefix: str) -> str:
+    """Build the HA Discovery config topic for *entity*.
+
+    Format: ``<prefix>/<component>/<node_id>/<object_id>/config``
+    """
+    node = _node_id(entity.device.identifiers[1])  # device uuid
+    obj = _object_id(entity)
+    return f"{prefix}/{entity.component}/{node}/{obj}/config"
+
+
+def _state_topic(entity: ExposableEntity, prefix: str) -> str:
+    """Build the state publish topic for *entity*.
+
+    Format: ``<prefix>/<component>/<node_id>/<object_id>/state``
+    """
+    node = _node_id(entity.device.identifiers[1])
+    obj = _object_id(entity)
+    return f"{prefix}/{entity.component}/{node}/{obj}/state"
+
+
+def _availability_topic(device_uuid: str, prefix: str) -> str:
+    """Shared availability topic for all entities of a device.
+
+    Format: ``<prefix>/modbus/<node_id>/availability``
+    """
+    node = _node_id(device_uuid)
+    return f"{prefix}/modbus/{node}/availability"
+
+
+def _unique_id(entity: ExposableEntity) -> str:
+    """Stable unique_id — device uuid + metric key (never from mutable fields)."""
+    device_uuid = entity.device.identifiers[1]
+    # entity.key is already "modbus.<uuid>.<metric_key>" — use it as the seed
+    return f"{device_uuid}_{entity.key.replace('.', '_')}"
+
+
+# ---------------------------------------------------------------------------
+# Public: build discovery payload
+# ---------------------------------------------------------------------------
+
+
+def build_discovery_payload(
+    entity: ExposableEntity,
+    discovery_prefix: str,
+    state_prefix: str | None = None,
+) -> tuple[str, dict[str, Any]]:
+    """Build the HA MQTT Discovery config topic and payload dict for *entity*.
+
+    Parameters
+    ----------
+    entity:
+        An ``ExposableEntity`` (from ``build_catalog``).
+    discovery_prefix:
+        The HA Discovery config topic prefix (e.g. ``"homeassistant"``).
+        This determines where HA looks for the discovery config topic.
+    state_prefix:
+        The prefix used for state and availability topics (e.g.
+        ``"home_automation"``).  When omitted or ``None``, falls back to
+        ``discovery_prefix`` for backward compatibility (e.g. in tests that
+        pass only one prefix).
+
+    Returns
+    -------
+    tuple[str, dict]
+        ``(topic, config_dict)`` — the config topic and the HA Discovery
+        payload (not yet JSON-serialised).
+    """
+    if state_prefix is None:
+        state_prefix = discovery_prefix
+
+    device_uuid = entity.device.identifiers[1]
+    avail_topic = _availability_topic(device_uuid, state_prefix)
+    state_t = _state_topic(entity, state_prefix)
+    topic = _discovery_topic(entity, discovery_prefix)
+
+    config: dict[str, Any] = {
+        "unique_id": _unique_id(entity),
+        "name": entity.name,
+        "state_topic": state_t,
+        "device": {
+            "identifiers": list(entity.device.identifiers),
+            "name": entity.device.name,
+        },
+    }
+
+    # Only declare an availability topic for devices that actually publish an
+    # online/offline heartbeat (e.g. Modbus, via its "online" binary_sensor).
+    # Devices without a heartbeat (e.g. energy-cost) omit availability so HA
+    # treats their entities as always-available — otherwise HA would mark them
+    # ``unavailable`` forever even though their state is being published.
+    if entity.device.provides_availability:
+        config["availability"] = [{"topic": avail_topic}]
+        config["availability_mode"] = "all"
+
+    # Component-specific fields
+    if entity.component == "binary_sensor":
+        # "online" binary sensor: payload ON/OFF
+        config["payload_on"] = "ON"
+        config["payload_off"] = "OFF"
+        if entity.device_class:
+            config["device_class"] = entity.device_class
+    else:
+        # sensor (and others)
+        if entity.device_class:
+            config["device_class"] = entity.device_class
+        if entity.unit:
+            config["unit_of_measurement"] = entity.unit
+        if entity.state_class:
+            config["state_class"] = entity.state_class
+
+    return topic, config
+
+
+# ---------------------------------------------------------------------------
+# Public: publish discovery
+# ---------------------------------------------------------------------------
+
+
+def publish_discovery(session: Session) -> None:
+    """Publish HA Discovery configs for all entities in the catalog.
+
+    - Enabled entities: publish retained JSON config payload.
+    - Disabled entities: publish empty (b"") payload to clear any previously
+      retained config from HA.
+
+    No-op if MQTT / discovery is not enabled or the client is not connected.
+    All MQTT errors are caught internally — this function never raises.
+    """
+    from app.config import get_settings
+    settings = build_runtime_settings(session, get_settings())
+    if not _should_publish(settings):
+        logger.debug("publish_discovery: skipped (MQTT/Discovery not enabled or not connected)")
+        return
+
+    discovery_prefix = settings.ha_discovery_prefix
+    state_prefix = settings.ha_state_topic_prefix
+
+    try:
+        catalog = build_catalog(session)
+    except Exception:
+        logger.exception("publish_discovery: failed to build catalog; aborting")
+        return
+
+    for entry in catalog:
+        entity = entry.entity
+        try:
+            topic, config = build_discovery_payload(entity, discovery_prefix, state_prefix)
+            if entry.enabled:
+                payload = json.dumps(config)
+                mqtt_manager.publish(topic, payload, retain=True)
+                logger.debug(
+                    "publish_discovery: published config for %r → %s", entity.key, topic
+                )
+            else:
+                # Clear retained config for disabled entities.
+                mqtt_manager.publish(topic, b"", retain=True)
+                logger.debug(
+                    "publish_discovery: cleared config for disabled entity %r → %s",
+                    entity.key,
+                    topic,
+                )
+        except Exception:
+            logger.exception(
+                "publish_discovery: error processing entity %r; continuing", entity.key
+            )
+
+
+# ---------------------------------------------------------------------------
+# Public: publish states
+# ---------------------------------------------------------------------------
+
+
+def publish_states(session: Session) -> None:
+    """Publish current state values for all enabled entities.
+
+    Calls each entity's ``value_getter`` to obtain the current value and
+    publishes it to the entity's state topic.  Also publishes availability
+    (online/offline) for each device.
+
+    No-op if MQTT / discovery is not enabled or the client is not connected.
+    All errors are caught internally — this function never raises.
+    """
+    from app.config import get_settings
+    settings = build_runtime_settings(session, get_settings())
+    if not _should_publish(settings):
+        logger.debug("publish_states: skipped (MQTT/Discovery not enabled or not connected)")
+        return
+
+    state_prefix = settings.ha_state_topic_prefix
+
+    try:
+        catalog = build_catalog(session)
+    except Exception:
+        logger.exception("publish_states: failed to build catalog; aborting")
+        return
+
+    # Collect enabled entries and publish
+    for entry in catalog:
+        if not entry.enabled:
+            continue
+        entity = entry.entity
+        try:
+            _publish_entity_state(entity, state_prefix, session)
+        except Exception:
+            logger.exception(
+                "publish_states: error publishing state for %r; continuing", entity.key
+            )
+
+
+def _publish_entity_state(
+    entity: ExposableEntity,
+    prefix: str,
+    session: Session,
+) -> None:
+    """Publish one entity's current state value to its state topic.
+
+    Also publishes the availability topic for ``binary_sensor`` "online" entities.
+    """
+    state_t = _state_topic(entity, prefix)
+    device_uuid = entity.device.identifiers[1]
+
+    if entity.component == "binary_sensor" and "online" in entity.key:
+        # The online sensor represents device availability.
+        # Ask the value_getter for the current ON/OFF string, then also publish
+        # the shared availability topic (online/offline).
+        raw_value = None
+        if entity.value_getter is not None:
+            try:
+                raw_value = entity.value_getter(session)
+            except Exception:
+                logger.exception("value_getter raised for online entity %r", entity.key)
+        # Default to offline when no reading is available.
+        online = (raw_value == "ON")
+        avail_payload = "online" if online else "offline"
+        avail_topic = _availability_topic(device_uuid, prefix)
+        mqtt_manager.publish(avail_topic, avail_payload, retain=False)
+        # The state of the binary_sensor itself
+        state_payload = "ON" if online else "OFF"
+        mqtt_manager.publish(state_t, state_payload, retain=False)
+    else:
+        # Regular sensor: call value_getter(session) if available.
+        value = None
+        if entity.value_getter is not None:
+            try:
+                value = entity.value_getter(session)
+            except Exception:
+                logger.exception("value_getter raised for entity %r", entity.key)
+
+        if value is None:
+            logger.debug("publish_states: no value for %r — skipping state publish", entity.key)
+            return
+
+        mqtt_manager.publish(state_t, str(value), retain=False)
+
+
+# ---------------------------------------------------------------------------
+# Public: per-device state push (called by modbus_poll after each poll)
+# ---------------------------------------------------------------------------
+
+
+def publish_device_state(session: Session, device: Any) -> None:
+    """Publish state + availability for all enabled entities of *device*.
+
+    Called by ``modbus_poll.poll_device`` after a successful (or failed) poll.
+    Publishes:
+    - The current availability topic ("online" / "offline") for the device.
+    - The state topic for each **enabled** entity of the device.
+
+    No-op if MQTT / discovery is not enabled or the client is not connected.
+    All errors are caught internally — never raises.
+    """
+    from app.config import get_settings
+    settings = build_runtime_settings(session, get_settings())
+    if not _should_publish(settings):
+        return
+
+    state_prefix = settings.ha_state_topic_prefix
+    device_uuid = device.uuid
+    online = bool(device.last_poll_ok)
+
+    # Publish availability topic first.
+    try:
+        avail_topic = _availability_topic(device_uuid, state_prefix)
+        avail_payload = "online" if online else "offline"
+        mqtt_manager.publish(avail_topic, avail_payload, retain=False)
+    except Exception:
+        logger.exception(
+            "publish_device_state: failed to publish availability for device uuid=%s", device_uuid
+        )
+
+    if not online:
+        # Device is offline — no point pushing stale state values.
+        return
+
+    # Publish state for each enabled entity of this device.
+    try:
+        catalog = build_catalog(session)
+    except Exception:
+        logger.exception(
+            "publish_device_state: failed to build catalog for device uuid=%s", device_uuid
+        )
+        return
+
+    for entry in catalog:
+        if not entry.enabled:
+            continue
+        entity = entry.entity
+        # Only process entities belonging to this device.
+        if entity.device.identifiers[1] != device_uuid:
+            continue
+        # Skip the online binary_sensor itself (availability handled above).
+        if entity.component == "binary_sensor" and "online" in entity.key:
+            # Publish the binary_sensor state too.
+            try:
+                state_t = _state_topic(entity, state_prefix)
+                mqtt_manager.publish(state_t, "ON", retain=False)
+            except Exception:
+                logger.exception(
+                    "publish_device_state: error publishing online sensor state for %r",
+                    entity.key,
+                )
+            continue
+
+        # Regular sensor — call value_getter(session).
+        try:
+            value = None
+            if entity.value_getter is not None:
+                value = entity.value_getter(session)
+            if value is None:
+                continue
+            state_t = _state_topic(entity, state_prefix)
+            mqtt_manager.publish(state_t, str(value), retain=False)
+        except Exception:
+            logger.exception(
+                "publish_device_state: error publishing state for entity %r", entity.key
+            )
+
+
+def clear_device_discovery(session: Session, device_uuid: str) -> None:
+    """Best-effort: send empty retained payloads to all HA Discovery config topics
+    for the given device, effectively removing the device's entities from HA.
+
+    This must be called **before** the device rows are deleted from the DB, so
+    that ``build_catalog`` can still enumerate the device's entities.
+
+    Behaviour
+    ---------
+    - No-op if MQTT / HA Discovery is not enabled or the MQTT client is not
+      connected.
+    - All exceptions are caught internally; this function never raises.
+      The caller proceeds with the DB deletion regardless of MQTT outcome.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session (device must still exist in DB at call time).
+    device_uuid:
+        UUID string of the device being deleted.
+    """
+    from app.config import get_settings
+    settings = build_runtime_settings(session, get_settings())
+    if not _should_publish(settings):
+        logger.debug(
+            "clear_device_discovery: skipped (MQTT/Discovery not enabled or not connected)"
+        )
+        return
+
+    discovery_prefix = settings.ha_discovery_prefix
+    state_prefix = settings.ha_state_topic_prefix
+
+    try:
+        catalog = build_catalog(session)
+    except Exception:
+        logger.exception(
+            "clear_device_discovery: failed to build catalog for device uuid=%s; skipping HA cleanup",
+            device_uuid,
+        )
+        return
+
+    cleared = 0
+    for entry in catalog:
+        entity = entry.entity
+        # Only clear entities belonging to this device.
+        if entity.device.identifiers[1] != device_uuid:
+            continue
+        try:
+            topic, _config = build_discovery_payload(entity, discovery_prefix, state_prefix)
+            mqtt_manager.publish(topic, b"", retain=True)
+            cleared += 1
+            logger.debug(
+                "clear_device_discovery: cleared config topic for entity %r → %s",
+                entity.key,
+                topic,
+            )
+        except Exception:
+            logger.exception(
+                "clear_device_discovery: error clearing entity %r; continuing", entity.key
+            )
+
+    logger.info(
+        "clear_device_discovery: cleared %d HA discovery topic(s) for device uuid=%s",
+        cleared,
+        device_uuid,
+    )
+
+
+def publish_device_offline(session: Session, device_uuid: str) -> None:
+    """Publish an "offline" availability payload for *device_uuid*.
+
+    Called by ``modbus_poll.poll_device`` when a poll fails, to immediately
+    reflect the device going offline in HA (before the next full state sweep).
+
+    No-op if MQTT / discovery is not enabled or the client is not connected.
+    Never raises.
+    """
+    from app.config import get_settings
+    settings = build_runtime_settings(session, get_settings())
+    if not _should_publish(settings):
+        return
+
+    try:
+        state_prefix = settings.ha_state_topic_prefix
+        avail_topic = _availability_topic(device_uuid, state_prefix)
+        mqtt_manager.publish(avail_topic, "offline", retain=False)
+    except Exception:
+        logger.exception(
+            "publish_device_offline: failed for device uuid=%s", device_uuid
+        )
@@ -0,0 +1,179 @@
+"""Exponential back-off throttle service for the login endpoint.
+
+Design
+------
+Failures are tracked per (scope, key) in the ``auth_login_throttle`` table:
+
+* scope ``'ip'``   → key is the client IP address
+* scope ``'user'`` → key is the username
+
+On each login attempt the endpoint checks **both** keys and takes the **maximum**
+remaining wait (in seconds).  A wait > 0 means the caller is still inside a
+back-off window and should receive 429.
+
+Exponential formula
+-------------------
+The first ``N_FREE`` failures are free (no delay).  After that::
+
+    wait = min(BACKOFF_CAP_S, BACKOFF_BASE_S * 2 ** (failures - N_FREE))
+
+Constants (module-level so they can be tuned without touching the algorithm):
+
+* ``N_FREE``         = 3   — failures before any delay starts
+* ``BACKOFF_BASE_S`` = 1   — base wait in seconds (1st delayed attempt → 2 s)
+* ``BACKOFF_CAP_S``  = 900 — hard cap (15 min)
+
+Example delay schedule:
+  failures 1, 2, 3 → 0 s (free)
+  failures 4       → 2 s
+  failures 5       → 4 s
+  failures 6       → 8 s
+  failures 7       → 16 s
+  …
+  failures 13+     → 900 s (capped)
+
+Timezone notes
+--------------
+The model uses ``DateTime(timezone=True)``.  SQLite stores timestamps without
+timezone info, so when rows are read back the column value may be timezone-naive.
+We normalise every stored value to UTC-aware via ``_as_utc`` before comparing
+against ``datetime.now(UTC)``.
+"""
+
+from __future__ import annotations
+
+import math
+from datetime import UTC, datetime, timedelta
+
+from sqlalchemy import delete, select
+from sqlalchemy.orm import Session
+
+from app.models.auth_throttle import LoginThrottle
+
+# ---------------------------------------------------------------------------
+# Tunable constants
+# ---------------------------------------------------------------------------
+
+N_FREE: int = 3          # failures before any backoff starts
+BACKOFF_BASE_S: int = 1  # seconds — wait after the first delayed failure
+BACKOFF_CAP_S: int = 900  # seconds — maximum wait (15 min)
+
+# Internal scope labels (keep in sync with model constraint)
+_SCOPE_IP = "ip"
+_SCOPE_USER = "user"
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def check_and_get_wait(session: Session, *, ip: str, username: str) -> int:
+    """Return the number of seconds the caller must still wait, or 0 if allowed.
+
+    Checks both the IP row and the username row; returns the *larger* remaining
+    wait so that both keys must have their back-off window expire before the
+    caller is permitted to try again.
+    """
+    now = datetime.now(UTC)
+    wait_ip = _remaining_wait(session, scope=_SCOPE_IP, key=ip, now=now)
+    wait_user = _remaining_wait(session, scope=_SCOPE_USER, key=username, now=now)
+    return max(wait_ip, wait_user)
+
+
+def register_failure(session: Session, *, ip: str, username: str) -> None:
+    """Record one login failure for both the IP and the username keys.
+
+    Updates (or creates) the throttle row for each key, increments the failure
+    counter, and recomputes ``next_allowed_at`` using the exponential formula.
+    """
+    now = datetime.now(UTC)
+    _upsert_failure(session, scope=_SCOPE_IP, key=ip, now=now)
+    _upsert_failure(session, scope=_SCOPE_USER, key=username, now=now)
+    session.commit()
+
+
+def clear(session: Session, *, ip: str, username: str) -> None:
+    """Delete the throttle rows for the given IP and username (successful login).
+
+    It is safe to call this even if no rows exist for the given keys.
+    """
+    session.execute(
+        delete(LoginThrottle).where(
+            (LoginThrottle.scope == _SCOPE_IP) & (LoginThrottle.key == ip)
+            | (LoginThrottle.scope == _SCOPE_USER) & (LoginThrottle.key == username)
+        )
+    )
+    session.commit()
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _remaining_wait(session: Session, *, scope: str, key: str, now: datetime) -> int:
+    """Return the number of seconds that ``key`` in ``scope`` must still wait.
+
+    Returns 0 if the key has no throttle row or if the back-off window has
+    already expired.
+    """
+    row = session.scalar(
+        select(LoginThrottle)
+        .where(LoginThrottle.scope == scope, LoginThrottle.key == key)
+        .limit(1)
+    )
+    if row is None or row.next_allowed_at is None:
+        return 0
+
+    next_allowed = _as_utc(row.next_allowed_at)
+    if next_allowed <= now:
+        return 0
+
+    remaining = (next_allowed - now).total_seconds()
+    # Round up so callers are never told "0 seconds" while still blocked.
+    return math.ceil(remaining)
+
+
+def _compute_next_allowed_at(failures: int, now: datetime) -> datetime | None:
+    """Compute the earliest time the key should be allowed to try again.
+
+    Returns ``None`` for the first ``N_FREE`` failures (no delay).
+    """
+    if failures <= N_FREE:
+        return None
+    wait_s = min(BACKOFF_CAP_S, BACKOFF_BASE_S * (2 ** (failures - N_FREE)))
+    return now + timedelta(seconds=wait_s)
+
+
+def _upsert_failure(session: Session, *, scope: str, key: str, now: datetime) -> None:
+    """Create or update the throttle row for (scope, key) with one more failure."""
+    row = session.scalar(
+        select(LoginThrottle)
+        .where(LoginThrottle.scope == scope, LoginThrottle.key == key)
+        .limit(1)
+    )
+    if row is None:
+        new_failures = 1
+        row = LoginThrottle(
+            scope=scope,
+            key=key,
+            failures=new_failures,
+            first_failed_at=now,
+            last_failed_at=now,
+            next_allowed_at=_compute_next_allowed_at(new_failures, now),
+        )
+        session.add(row)
+    else:
+        row.failures += 1
+        row.last_failed_at = now
+        row.next_allowed_at = _compute_next_allowed_at(row.failures, now)
+
+
+def _as_utc(value: datetime | None) -> datetime | None:
+    """Normalise a possibly-naive datetime to UTC-aware."""
+    if value is None:
+        return None
+    if value.tzinfo is None:
+        return value.replace(tzinfo=UTC)
+    return value.astimezone(UTC)
@@ -0,0 +1,480 @@
+"""Service layer for Meter epoch CRUD, swap/close, and time-range lookup.
+
+All functions accept an explicit SQLAlchemy Session; callers are responsible
+for committing or rolling back the transaction.
+
+Design decisions
+----------------
+- ``meter_at``:       half-open interval ``[started_at, ended_at)`` lookup;
+  returns the meter whose epoch covers *ts* for the given commodity.
+  SQLite naive datetime is normalised via ``_as_utc()`` before comparison.
+
+- ``declare_meter``:  validates that the new ``started_at`` is **not earlier
+  than** the current active meter's ``started_at`` (rejects back-dating below
+  the active meter's own start).  Equal timestamps are allowed because the
+  typical "swap now" use-case sets ``started_at`` to the current moment, which
+  coincides with the active meter's ``started_at`` only in degenerate test
+  scenarios — but blocking equal values would make that workflow impossible.
+  The old active meter is closed (``ended_at = started_at``) and a new active
+  meter is opened in the same operation, guaranteeing continuity: the old
+  meter's ``ended_at`` equals the new meter's ``started_at`` (contiguous,
+  no gap, no overlap).
+
+- ``update_meter``:   when ``started_at`` is modified, the service keeps the
+  timeline contiguous by also updating the **previous** meter's ``ended_at``
+  (the one whose ``ended_at`` matched the old ``started_at``) to the new
+  ``started_at``.  Validation ensures the new ``started_at``:
+    * is strictly after the previous meter's own ``started_at``
+      (cannot push the boundary before the previous meter even started);
+    * is strictly before the current meter's ``ended_at``, if set
+      (cannot push the boundary past where the current meter was already
+      closed).
+
+- Mutual exclusion (at most one active meter per commodity) is enforced by the
+  service layer; no DB-level unique partial index is added to keep migrations
+  simple and to allow the application to return a meaningful error message.
+
+SQLite timezone note
+--------------------
+SQLite stores ``DateTime(timezone=True)`` columns as naive UTC strings; on
+read-back they come out as **timezone-naive** datetimes.  Wherever this code
+compares timestamps from the DB against timezone-aware values, it calls
+``_as_utc()`` to make both sides comparable without tripping on
+"offset-naive vs offset-aware" TypeErrors.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+from typing import Optional
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.models.energy import Meter
+
+logger = logging.getLogger(__name__)
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _as_utc(dt: datetime) -> datetime:
+    """Return *dt* as a timezone-aware UTC datetime.
+
+    SQLite's ``DateTime(timezone=True)`` column type stores datetimes as naive
+    UTC strings and gives them back as naive datetimes on read.  This helper
+    re-attaches the UTC timezone info when it is missing, making cross-origin
+    comparisons safe.
+    """
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=UTC)
+    return dt
+
+
+# ---------------------------------------------------------------------------
+# Custom exceptions
+# ---------------------------------------------------------------------------
+
+
+class MeterError(ValueError):
+    """Base class for meter service validation errors."""
+
+
+class MeterOverlapError(MeterError):
+    """Raised when a new meter's ``started_at`` would create an overlap or backdate.
+
+    Specifically: the new meter's ``started_at`` must be greater than or equal
+    to the current active meter's ``started_at``.  Allowing a value strictly
+    earlier than the active meter's start would mean the new epoch begins before
+    the current one, which is chronologically inconsistent.
+    """
+
+
+class MeterIntervalError(MeterError):
+    """Raised when an ``update_meter`` call would produce an inconsistent interval.
+
+    Examples of inconsistent intervals:
+    - New ``started_at`` ≥ this meter's ``ended_at`` (epoch would be empty/inverted).
+    - New ``started_at`` ≤ the previous meter's own ``started_at`` (previous meter
+      would become empty/inverted after its ``ended_at`` is updated).
+    """
+
+
+# ---------------------------------------------------------------------------
+# Internal query helpers
+# ---------------------------------------------------------------------------
+
+
+def _active_meter(session: Session, commodity: str) -> Optional[Meter]:
+    """Return the current active (``ended_at IS NULL``) meter for *commodity*, or None."""
+    return session.execute(
+        select(Meter)
+        .where(
+            Meter.commodity == commodity,
+            Meter.ended_at.is_(None),
+        )
+        .limit(1)
+    ).scalar_one_or_none()
+
+
+def _meter_before(session: Session, meter: Meter) -> Optional[Meter]:
+    """Return the meter whose ``ended_at`` equals *meter*'s ``started_at``.
+
+    This is the meter that was closed when *meter* was opened; its ``ended_at``
+    needs to stay equal to *meter*'s ``started_at`` to maintain timeline
+    continuity.  Returns None if *meter* is the first epoch for its commodity.
+
+    The lookup compares naive/aware datetimes via string to avoid SQLite timezone
+    quirks: both are formatted as ISO 8601 UTC strings for the WHERE clause.
+    We rely on the fact that the service layer always stores the same timestamp
+    object as both ``prev.ended_at`` and ``new.started_at``, so their string
+    representations are identical.
+    """
+    # Normalise the target to a tz-aware UTC datetime for comparison.
+    # We scan in Python (rather than SQL) to avoid SQLite naive-vs-aware
+    # mismatch issues when comparing DateTime columns against tz-aware values.
+    target = _as_utc(meter.started_at)
+
+    # Fetch all closed meters of the same commodity and find the one whose
+    # ended_at equals this meter's started_at (the standard contiguous handoff).
+    candidates = session.execute(
+        select(Meter)
+        .where(
+            Meter.commodity == meter.commodity,
+            Meter.ended_at.is_not(None),
+        )
+    ).scalars().all()
+
+    for candidate in candidates:
+        if candidate.id == meter.id:
+            continue
+        candidate_ended = _as_utc(candidate.ended_at)
+        if candidate_ended == target:
+            return candidate
+
+    return None
+
+
+# ---------------------------------------------------------------------------
+# Core service functions
+# ---------------------------------------------------------------------------
+
+
+def meter_at(
+    session: Session,
+    ts: datetime,
+    commodity: str = "electricity",
+) -> Optional[Meter]:
+    """Return the meter epoch that covers *ts* for *commodity*.
+
+    A meter covers *ts* when:
+        ``started_at ≤ ts`` AND (``ended_at IS NULL`` OR ``ts < ended_at``)
+
+    This is the standard half-open interval ``[started_at, ended_at)`` lookup,
+    consistent with ``active_contract_version_at`` in ``contracts.py``.
+
+    Returns ``None`` when no meter covers *ts* (e.g. before the first epoch
+    was declared, or after a gap).
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session (read-only usage).
+    ts:
+        UTC datetime to look up.
+    commodity:
+        Energy commodity (default ``"electricity"``).
+
+    Returns
+    -------
+    Meter | None
+
+    Implementation note — why the upper bound is pushed into SQL
+    ------------------------------------------------------------
+    When ``declare_meter`` is called with ``started_at == active.started_at``
+    (the "equal-timestamp swap" allowed by §3.5), the old meter is closed as a
+    zero-width epoch ``[T0, T0)`` and the new active meter also has
+    ``started_at == T0``.  Two rows share the same ``started_at``; SQLite's
+    row-ordering for ``ORDER BY started_at DESC LIMIT 1`` is then determined by
+    rowid (i.e. insertion order), which returns the older zero-width row first.
+
+    If the upper bound were checked in Python *after* fetching that one row, the
+    condition ``ts < ended_at`` would be False for **any** ``ts >= T0`` (because
+    ``ended_at == T0``), causing the function to return ``None`` and making the
+    new active meter permanently invisible.
+
+    Pushing both bounds into the SQL ``WHERE`` clause eliminates the ambiguity:
+    the zero-width row is excluded by ``ts < ended_at`` before ``LIMIT 1`` is
+    applied, so only the genuinely covering row survives.
+
+    SQLite naive-vs-aware datetime note: SQLAlchemy's SQLite dialect strips the
+    ``tzinfo`` from aware datetimes when binding parameters (it does *not*
+    convert to UTC first).  Since all datetimes in this codebase are UTC (either
+    naive-UTC from the DB or aware-UTC from ``datetime.now(UTC)``), stripping
+    the tzinfo leaves the wall-clock value unchanged and comparisons remain
+    correct.  This is consistent with how ``contracts.py`` handles the same
+    situation (see OBS 2 in the M7-T02 review notes).
+    """
+    # Push both the lower and upper bounds into the SQL WHERE clause so that
+    # zero-width epochs (ended_at == started_at) are excluded *before* LIMIT 1
+    # is applied.  This prevents an equal-timestamp swap from making the new
+    # active meter invisible (see implementation note above).
+    stmt = (
+        select(Meter)
+        .where(
+            Meter.commodity == commodity,
+            Meter.started_at <= ts,
+            (Meter.ended_at.is_(None)) | (Meter.ended_at > ts),
+        )
+        .order_by(Meter.started_at.desc())
+        .limit(1)
+    )
+    return session.execute(stmt).scalar_one_or_none()
+
+
+def declare_meter(
+    session: Session,
+    *,
+    label: str,
+    started_at: datetime,
+    reason: str,
+    commodity: str = "electricity",
+    note: Optional[str] = None,
+) -> Meter:
+    """Declare a meter swap or initial meter epoch.
+
+    Closes the current active meter for *commodity* (if one exists) by setting
+    its ``ended_at`` to *started_at*, then opens a new active meter.  The
+    resulting timeline is **contiguous**: old meter's ``ended_at`` equals new
+    meter's ``started_at``.
+
+    If there is no current active meter (first-ever declaration for this
+    commodity), the new meter is simply opened without closing anything.
+
+    Validation
+    ----------
+    - If a current active meter exists, *started_at* must be **≥** that meter's
+      own ``started_at``.  A value strictly earlier would place the new epoch
+      entirely before the current active meter, which is a chronological
+      contradiction ("back-dating before the active epoch's start").  Raises
+      ``MeterOverlapError`` when this constraint is violated.
+
+    Note: equal timestamps (``started_at == active.started_at``) are allowed
+    because that scenario effectively replaces the current meter at the same
+    logical moment (e.g. correcting a mis-entry), which is a valid use-case.
+    The old meter is then closed with ``ended_at == started_at`` (a zero-width
+    epoch), which is intentional and auditable.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  Caller must commit after this returns.
+    label:
+        Human-readable label for the new meter.
+    started_at:
+        UTC datetime at which this meter epoch starts.  May be in the past.
+    reason:
+        Why this epoch was created (``"initial"``, ``"meter_swap"``,
+        ``"home_move"``, or ``"other"``).
+    commodity:
+        Energy commodity (default ``"electricity"``).
+    note:
+        Optional free-form note.
+
+    Returns
+    -------
+    Meter
+        The newly created, not-yet-committed active meter.
+
+    Raises
+    ------
+    MeterOverlapError
+        If *started_at* is strictly earlier than the current active meter's
+        ``started_at`` (chronological backdate below the active epoch's start).
+    """
+    active = _active_meter(session, commodity)
+
+    if active is not None:
+        # Reject back-dating: new started_at must be ≥ current active's started_at.
+        if _as_utc(started_at) < _as_utc(active.started_at):
+            raise MeterOverlapError(
+                f"New meter started_at ({started_at.isoformat()}) must be ≥ the current "
+                f"active {commodity!r} meter's started_at "
+                f"({active.started_at.isoformat()}).  "
+                "Declare a started_at on or after the active meter's start to avoid "
+                "a chronologically inconsistent epoch ordering."
+            )
+        # Close the current active meter at the swap point (contiguous handoff).
+        active.ended_at = started_at
+        logger.info(
+            "Closed active %r meter id=%d (ended_at=%s)",
+            commodity,
+            active.id,
+            started_at.isoformat(),
+        )
+
+    now = datetime.now(UTC)
+    new_meter = Meter(
+        label=label,
+        commodity=commodity,
+        started_at=started_at,
+        ended_at=None,
+        reason=reason,
+        note=note,
+        created_at=now,
+    )
+    session.add(new_meter)
+
+    logger.info(
+        "Declared new %r meter %r (started_at=%s, reason=%s)",
+        commodity,
+        label,
+        started_at.isoformat(),
+        reason,
+    )
+    return new_meter
+
+
+def list_meters(
+    session: Session,
+    commodity: Optional[str] = None,
+) -> list[Meter]:
+    """List all meter epochs, ordered by started_at ascending.
+
+    Active meters (``ended_at IS NULL``) sort naturally to the end of the
+    timeline since they have the latest ``started_at``.  Within a single
+    commodity, the ascending ``started_at`` order reflects the historical
+    sequence of installed meters.
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session (read-only usage).
+    commodity:
+        If provided, filter to this commodity only.  If ``None``, return all
+        meters across all commodities.
+
+    Returns
+    -------
+    list[Meter]
+        Meters ordered by (started_at ASC).
+    """
+    stmt = select(Meter).order_by(Meter.started_at.asc())
+    if commodity is not None:
+        stmt = stmt.where(Meter.commodity == commodity)
+
+    return list(session.execute(stmt).scalars().all())
+
+
+def update_meter(
+    session: Session,
+    meter: Meter,
+    *,
+    label: Optional[str] = None,
+    note: Optional[str] = None,
+    started_at: Optional[datetime] = None,
+) -> Meter:
+    """Update a meter's mutable fields (label, note, started_at).
+
+    Passing ``None`` for a field leaves it unchanged.  At least one keyword
+    argument must be non-``None``; calling with all-``None`` is a no-op but
+    is not an error.
+
+    Updating ``started_at`` (retroactive correction)
+    ------------------------------------------------
+    When ``started_at`` is provided the service maintains **timeline
+    continuity** across the adjacent meter boundaries:
+
+    1. **Previous meter's ``ended_at``** — if the meter immediately before
+       this one has ``ended_at == meter.started_at`` (the standard contiguous
+       handoff), its ``ended_at`` is updated to the new ``started_at`` so the
+       boundary between the two epochs stays seamless.
+
+    2. **Validation** — the new ``started_at`` is checked for consistency:
+       a. It must be **strictly after** the previous meter's own ``started_at``
+          (otherwise the previous meter's epoch would collapse to zero or
+          invert).
+       b. It must be **strictly before** this meter's ``ended_at`` (if set),
+          so this meter's epoch remains non-empty.
+
+    Note: triggering a billing recompute (``recompute_range``) after a
+    retroactive ``started_at`` change is **out of scope** for this service
+    layer; that is the API layer's responsibility (M7-T05).
+
+    Parameters
+    ----------
+    session:
+        Active SQLAlchemy session.  Caller must commit after this returns.
+    meter:
+        The ``Meter`` ORM instance to update (already loaded from the session).
+    label:
+        New human-readable label; ``None`` = keep existing.
+    note:
+        New free-form note; ``None`` = keep existing.
+    started_at:
+        New start timestamp for this meter epoch; ``None`` = keep existing.
+
+    Returns
+    -------
+    Meter
+        The updated ``Meter`` instance (not yet committed).
+
+    Raises
+    ------
+    MeterIntervalError
+        If the new ``started_at`` would produce an invalid (empty or inverted)
+        epoch for this meter or the immediately preceding one.
+    """
+    if label is not None:
+        meter.label = label
+        logger.info("Updated meter id=%d label=%r", meter.id, label)
+
+    if note is not None:
+        meter.note = note
+        logger.info("Updated meter id=%d note=%r", meter.id, note)
+
+    if started_at is not None:
+        old_started_at = meter.started_at
+
+        # --- Validate upper bound: new started_at must be < this meter's ended_at (if set).
+        if meter.ended_at is not None:
+            if _as_utc(started_at) >= _as_utc(meter.ended_at):
+                raise MeterIntervalError(
+                    f"New started_at ({started_at.isoformat()}) must be strictly before "
+                    f"this meter's ended_at ({meter.ended_at.isoformat()}).  "
+                    "The meter epoch would become empty or inverted."
+                )
+
+        # --- Find the immediately preceding meter (its ended_at == meter's old started_at).
+        prev = _meter_before(session, meter)
+
+        # --- Validate lower bound: new started_at must be strictly after prev's started_at.
+        if prev is not None:
+            if _as_utc(started_at) <= _as_utc(prev.started_at):
+                raise MeterIntervalError(
+                    f"New started_at ({started_at.isoformat()}) must be strictly after "
+                    f"the previous meter's started_at ({prev.started_at.isoformat()}).  "
+                    "Moving the boundary that far back would collapse the previous meter's epoch."
+                )
+            # Maintain continuity: update the previous meter's ended_at to match the new start.
+            prev.ended_at = started_at
+            logger.info(
+                "Updated previous meter id=%d ended_at=%s (boundary shift from %s)",
+                prev.id,
+                started_at.isoformat(),
+                old_started_at.isoformat(),
+            )
+
+        meter.started_at = started_at
+        logger.info(
+            "Updated meter id=%d started_at=%s (was %s)",
+            meter.id,
+            started_at.isoformat(),
+            old_started_at.isoformat(),
+        )
+
+    return meter
@@ -0,0 +1,209 @@
+"""Modbus polling service — periodic read-and-store for enabled Modbus devices.
+
+Design notes
+------------
+- ``poll_device`` loads the device's YAML profile, calls the driver to bulk-read
+  all register blocks in a single TCP connection, decodes the raw registers into
+  an engineering-value dict via the profile, and persists one ``ModbusReading``
+  row.  It also stamps ``last_poll_at`` / ``last_poll_ok`` on the device.
+- All exceptions are caught and logged inside ``poll_device``; the function
+  never re-raises.  This prevents a single broken device from aborting the
+  sweep for all other devices.
+- ``poll_all_enabled_devices`` respects per-device ``poll_interval_s``: it skips
+  a device whose ``last_poll_at`` is recent enough.  This lets the APScheduler
+  job run on a short base tick (e.g. 5 s) while each device self-regulates its
+  own cadence.
+- The global ``modbus_polling_enabled`` flag from ``Settings`` (merged with any
+  DB overrides via ``build_runtime_settings``) gates the entire sweep as a
+  no-op.  T08 will expose this flag in CONFIG_FIELDS/UI; for now it is
+  controlled by the ``MODBUS_POLLING_ENABLED`` env var (or the default True).
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.config import Settings
+from app.integrations.modbus import driver, profiles
+from app.models.modbus import ModbusDevice, ModbusReading
+from app.services.config_page import build_runtime_settings
+from app.services.ha_discovery import publish_device_offline, publish_device_state
+
+logger = logging.getLogger(__name__)
+
+# Base polling tick in seconds (used by APScheduler; each device checks its own interval).
+BASE_POLL_TICK_SECONDS = 5
+
+
+def poll_device(session: Session, device: ModbusDevice) -> ModbusReading | None:
+    """Read one enabled Modbus device, decode, and persist a reading row.
+
+    Parameters
+    ----------
+    session:
+        Open SQLAlchemy session.  The caller is responsible for session
+        lifecycle (open / commit / close).
+    device:
+        ``ModbusDevice`` ORM instance to poll.
+
+    Returns
+    -------
+    ModbusReading | None
+        The newly-persisted reading on success, or ``None`` on any failure.
+        Failure is logged and the device's ``last_poll_ok`` is set to ``False``.
+    """
+    now = datetime.now(UTC)
+    try:
+        profile = profiles.load_profile(device.profile)
+        registers = driver.read_blocks(
+            device.host,
+            device.port,
+            device.unit_id,
+            [{"start": b.start, "count": b.count} for b in profile.blocks],
+        )
+        payload = profiles.decode(profile, registers)
+
+        reading = ModbusReading(
+            device_id=device.id,
+            recorded_at=now,
+            payload=payload,
+        )
+        session.add(reading)
+
+        device.last_poll_at = now
+        device.last_poll_ok = True
+        session.commit()
+
+        logger.debug(
+            "Polled device %r (id=%d): %d metrics recorded at %s",
+            device.friendly_name,
+            device.id,
+            len(payload),
+            now.isoformat(),
+        )
+
+        # Best-effort: push MQTT state after successful poll.
+        # Must never let MQTT errors crash the poll loop.
+        try:
+            publish_device_state(session, device)
+        except Exception:  # noqa: BLE001
+            logger.exception(
+                "poll_device: MQTT state publish failed for device %r (id=%d); "
+                "continuing (poll itself succeeded)",
+                device.friendly_name,
+                device.id,
+            )
+
+        return reading
+
+    except Exception:  # noqa: BLE001
+        logger.exception(
+            "Failed to poll device %r (id=%d, host=%s:%d, unit_id=%d)",
+            device.friendly_name,
+            device.id,
+            device.host,
+            device.port,
+            device.unit_id,
+        )
+        # Rollback first — if session.add(reading) already ran in the success
+        # branch before commit() failed, that pending ModbusReading must be
+        # discarded.  Without rollback it would remain staged and could be
+        # flushed/committed by a subsequent operation (even for a different
+        # device), producing a spurious reading row for a poll that failed.
+        # Rollback also expires all ORM objects; device fields are re-set below.
+        try:
+            session.rollback()
+        except Exception:  # noqa: BLE001
+            logger.exception(
+                "session.rollback() failed for device id=%d; session may be unusable", device.id
+            )
+        try:
+            device.last_poll_at = now
+            device.last_poll_ok = False
+            session.commit()
+        except Exception:  # noqa: BLE001
+            logger.exception(
+                "Also failed to persist last_poll_ok=False for device id=%d", device.id
+            )
+
+        # Best-effort: publish "offline" availability after failed poll.
+        try:
+            publish_device_offline(session, device.uuid)
+        except Exception:  # noqa: BLE001
+            logger.exception(
+                "poll_device: MQTT offline publish failed for device %r (id=%d)",
+                device.friendly_name,
+                device.id,
+            )
+
+        return None
+
+
+def poll_all_enabled_devices(
+    session: Session,
+    *,
+    bootstrap_settings: Settings,
+) -> None:
+    """Sweep all enabled Modbus devices and poll each one whose interval has elapsed.
+
+    Global kill-switch: if ``build_runtime_settings(...).modbus_polling_enabled``
+    is ``False``, this function returns immediately without touching any device.
+
+    Per-device interval: a device is skipped if its ``last_poll_at`` is not yet
+    ``poll_interval_s`` seconds in the past.  This allows the APScheduler job to
+    run on a short fixed tick while each device self-regulates its own cadence.
+
+    Exceptions from individual devices are swallowed inside ``poll_device``;
+    this function itself will not raise.
+
+    Parameters
+    ----------
+    session:
+        Open SQLAlchemy session.
+    bootstrap_settings:
+        The bootstrap ``Settings`` instance (from ``get_settings()``), used as
+        the base for ``build_runtime_settings`` to pick up any DB overrides.
+    """
+    try:
+        runtime_settings = build_runtime_settings(session, bootstrap_settings)
+    except Exception:  # noqa: BLE001
+        logger.exception("Failed to build runtime settings for Modbus poll; aborting sweep")
+        return
+
+    if not runtime_settings.modbus_polling_enabled:
+        logger.debug("Modbus polling is disabled (modbus_polling_enabled=False); skipping sweep")
+        return
+
+    try:
+        devices = session.execute(
+            select(ModbusDevice).where(ModbusDevice.enabled == True)  # noqa: E712
+        ).scalars().all()
+    except Exception:  # noqa: BLE001
+        logger.exception("Failed to query enabled Modbus devices; aborting sweep")
+        return
+
+    now = datetime.now(UTC)
+    for device in devices:
+        # Respect per-device poll interval: skip if last poll was too recent.
+        if device.last_poll_at is not None:
+            # SQLite may return a naive datetime despite DateTime(timezone=True) —
+            # treat naive values as UTC so the comparison is safe.
+            last_poll = device.last_poll_at
+            if last_poll.tzinfo is None:
+                last_poll = last_poll.replace(tzinfo=UTC)
+            elapsed = (now - last_poll).total_seconds()
+            if elapsed < device.poll_interval_s:
+                logger.debug(
+                    "Skipping device %r (id=%d): %.1fs elapsed < %ds interval",
+                    device.friendly_name,
+                    device.id,
+                    elapsed,
+                    device.poll_interval_s,
+                )
+                continue
+
+        poll_device(session, device)
@@ -0,0 +1,139 @@
+"""Service layer for fetching and persisting Tibber 15-minute electricity prices.
+
+``refresh_prices`` is the main entry point.  It is designed to be called from a
+scheduled background job (see ``app/main.py``) and from tests.
+
+Design decisions
+----------------
+- **Guard clause**: if no active contract with ``kind="tibber"`` exists, or if
+  the Tibber API token is empty in the runtime settings, the function is a
+  complete no-op (returns 0) and does not raise.  This means the scheduler can
+  call ``refresh_prices`` unconditionally; the service itself decides whether to
+  do anything based on current configuration.
+- **Upsert idempotency**: rows are matched by ``starts_at`` (the unique
+  constraint on ``tibber_price``).  If a row already exists, its price fields
+  and ``fetched_at`` are updated in-place; if it does not exist, a new row is
+  inserted.  Running ``refresh_prices`` twice in a row must not double-insert.
+- **No destructive operations**: this service never deletes ``tibber_price``
+  rows.  Only INSERT or UPDATE.
+- **Exception propagation**: exceptions from the Tibber client are *not*
+  swallowed here.  The scheduled job wrapper in ``main.py`` is responsible for
+  catching and logging errors so that a single fetch failure does not crash the
+  scheduler.
+- **SQLite timezone note**: ``DateTime(timezone=True)`` columns come back as
+  timezone-naive UTC datetimes on read.  We store UTC-aware datetimes on write
+  (``starts_at`` from ``PricePoint`` is already UTC-aware; ``fetched_at`` is
+  ``datetime.now(UTC)``).  Reads elsewhere that compare against these values
+  must normalise accordingly.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.integrations.tibber.client import fetch_price_range
+from app.models.energy import EnergyContract, TibberPrice
+
+logger = logging.getLogger(__name__)
+
+
+def _active_tibber_contract_exists(session: Session) -> bool:
+    """Return True if there is an active contract with kind='tibber'."""
+    row = session.execute(
+        select(EnergyContract).where(
+            EnergyContract.active.is_(True),
+            EnergyContract.kind == "tibber",
+        ).limit(1)
+    ).scalar_one_or_none()
+    return row is not None
+
+
+def refresh_prices(session: Session, settings: object) -> int:
+    """Fetch today-and-tomorrow Tibber prices and upsert them into ``tibber_price``.
+
+    Parameters
+    ----------
+    session:
+        An active SQLAlchemy session.  The caller is responsible for closing it;
+        this function commits each upserted row individually to keep transactions
+        short.
+    settings:
+        A runtime settings object that exposes ``tibber_api_token`` and
+        ``tibber_home_id`` attributes (typically a ``Settings`` or merged
+        runtime-settings instance from ``build_runtime_settings``).
+
+    Returns
+    -------
+    int
+        Number of rows upserted (inserted or updated).  Returns 0 for a no-op.
+
+    Notes
+    -----
+    - No-op (returns 0) when:
+        * No active contract exists with ``kind="tibber"``, OR
+        * ``settings.tibber_api_token`` is empty or whitespace.
+    - Exceptions from the Tibber client are *not* caught here; they propagate to
+      the caller (the scheduled job wrapper swallows them and logs).
+    """
+    token: str = getattr(settings, "tibber_api_token", "") or ""
+    if not token.strip():
+        logger.debug("refresh_prices: tibber_api_token is empty — no-op")
+        return 0
+
+    if not _active_tibber_contract_exists(session):
+        logger.debug("refresh_prices: no active tibber contract — no-op")
+        return 0
+
+    home_id: str = getattr(settings, "tibber_home_id", "") or ""
+    home_id_or_none: str | None = home_id.strip() or None
+
+    logger.info("refresh_prices: fetching Tibber price range (home_id=%r)", home_id_or_none)
+
+    # May raise TibberError or TibberAuthError — let them propagate.
+    price_points = fetch_price_range(token, home_id_or_none)
+
+    if not price_points:
+        logger.info("refresh_prices: API returned zero price points — nothing to upsert")
+        return 0
+
+    fetched_at = datetime.now(UTC)
+    upserted = 0
+
+    for point in price_points:
+        existing = session.execute(
+            select(TibberPrice).where(TibberPrice.starts_at == point.starts_at)
+        ).scalar_one_or_none()
+
+        if existing is not None:
+            # Update in-place — price fields may change (e.g. Tibber corrects a
+            # forecast), but starts_at and resolution stay the same.
+            existing.total = point.total
+            existing.energy = point.energy
+            existing.tax = point.tax
+            existing.level = point.level
+            existing.currency = point.currency
+            existing.fetched_at = fetched_at
+        else:
+            session.add(
+                TibberPrice(
+                    starts_at=point.starts_at,
+                    resolution=point.resolution,
+                    total=point.total,
+                    energy=point.energy,
+                    tax=point.tax,
+                    level=point.level,
+                    currency=point.currency,
+                    fetched_at=fetched_at,
+                )
+            )
+
+        upserted += 1
+
+    session.commit()
+
+    logger.info("refresh_prices: upserted %d price points", upserted)
+    return upserted
@@ -0,0 +1,100 @@
+"""Server local-timezone helpers.
+
+All time is stored as UTC (no change).  This module provides a single,
+monkeypatch-friendly entry point for converting UTC moments to the server's
+local timezone — used for business-day boundary calculations (standing charges,
+effective-from date interpretation, etc.).
+
+Design goals
+------------
+- Zero third-party dependencies (no tzlocal, no pytz).
+- Testable without depending on CI host timezone:
+  monkeypatch ``local_tz`` to a fixed ``ZoneInfo`` in unit tests.
+- DST-correct: conversions use ``astimezone(local_tz())`` per instant, so each
+  moment is independently correct even during DST transitions.
+- Consistent with the existing ``.astimezone()`` pattern already used in
+  ``homeassistant_inbound.py`` and ``poo.py``.
+
+Priority for resolving the local timezone
+-----------------------------------------
+1. ``TZ`` environment variable — ``ZoneInfo(os.environ["TZ"])``.
+   Set ``TZ=Europe/Amsterdam`` in the deployment env for correct NL handling.
+2. System local timezone fallback: ``datetime.now().astimezone().tzinfo``.
+   This matches the behaviour callers already relied on implicitly.
+"""
+
+from __future__ import annotations
+
+import os
+from datetime import date, datetime, timezone
+from typing import TYPE_CHECKING
+from zoneinfo import ZoneInfo
+
+if TYPE_CHECKING:
+    from datetime import tzinfo
+
+
+def local_tz() -> "tzinfo":
+    """Return the server's local timezone.
+
+    Resolution order:
+    1. ``TZ`` environment variable (``ZoneInfo(TZ)``).  Set
+       ``TZ=Europe/Amsterdam`` in production for correct NL/DST handling.
+    2. System local timezone via ``datetime.now().astimezone().tzinfo``.
+
+    **Monkeypatch this function in tests** to get deterministic timezone
+    behaviour regardless of CI host configuration::
+
+        monkeypatch.setattr("app.services.timezone.local_tz",
+                            lambda: ZoneInfo("Europe/Amsterdam"))
+    """
+    tz_env = os.environ.get("TZ", "").strip()
+    if tz_env:
+        return ZoneInfo(tz_env)
+    # System fallback — identical to the .astimezone() pattern already used
+    # in homeassistant_inbound.py and poo.py.
+    return datetime.now().astimezone().tzinfo  # type: ignore[return-value]
+
+
+def to_local(dt: datetime) -> datetime:
+    """Convert *dt* to the server local timezone.
+
+    Handles three input cases:
+    - timezone-aware (any zone): converted via ``astimezone``.
+    - timezone-naive: assumed UTC (SQLite read-back convention), then converted.
+
+    Returns a timezone-aware datetime in ``local_tz()``.
+    """
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    return dt.astimezone(local_tz())
+
+
+def local_now() -> datetime:
+    """Return the current moment as a timezone-aware local datetime."""
+    return datetime.now(local_tz())
+
+
+def local_date(dt: datetime) -> date:
+    """Return the local calendar date for *dt*.
+
+    Equivalent to ``to_local(dt).date()``.  A distinct helper to make
+    call sites readable.
+    """
+    return to_local(dt).date()
+
+
+def local_midnight_utc(d: date) -> datetime:
+    """Return the UTC instant that corresponds to local midnight on *d*.
+
+    Example (Europe/Amsterdam, CEST=UTC+2):
+        local_midnight_utc(date(2026, 6, 25))
+        → datetime(2026, 6, 24, 22, 0, 0, tzinfo=UTC)
+
+    This is used to convert a local calendar date back to a UTC boundary, e.g.
+    to compute the start/end of a local day for DB queries.
+    """
+    tz = local_tz()
+    # Build a naive local datetime at midnight, then localize and convert to UTC.
+    local_midnight = datetime(d.year, d.month, d.day, 0, 0, 0, tzinfo=tz)
+    return local_midnight.astimezone(timezone.utc)
@@ -0,0 +1,234 @@
+"""TOTP service: secret management, recovery-code lifecycle, setup/enable/disable (M4-T05).
+
+State-machine summary
+---------------------
+DISABLED (default)
+  totp_secret=None, totp_enabled=False, no recovery codes
+
+PENDING (after setup, before enable)
+  totp_secret=<base32>, totp_enabled=False, recovery codes stored as hashes
+  - Re-calling setup replaces the pending secret and regenerates recovery codes.
+
+ENABLED (after enable)
+  totp_secret=<base32>, totp_enabled=True, recovery codes stored as hashes
+
+After disable:
+  totp_secret=None, totp_enabled=False, recovery codes deleted  → back to DISABLED
+
+
+Recovery-code timing
+--------------------
+1. setup  → generate 10 plaintext codes, persist their Argon2 hashes immediately,
+            return plaintext to caller (ONLY time).
+2. enable → verify 6-digit TOTP code; if ok, flip totp_enabled=True.
+            Recovery codes are already in the DB from step 1.
+3. disable → clear secret, clear enabled flag, delete all recovery codes.
+
+Security note: ``totp_secret`` is stored as plaintext (same posture as other
+secrets in this project: protected by file-system permissions on the SQLite
+database).  Recovery codes are stored as Argon2 hashes only.
+"""
+from __future__ import annotations
+
+import logging
+import secrets
+import string
+
+import pyotp
+from sqlalchemy import delete, select
+from sqlalchemy.orm import Session
+
+from app.models.auth import AuthUser, RecoveryCode
+from app.services.auth import hash_password, verify_password
+
+logger = logging.getLogger(__name__)
+
+# Number of recovery codes to generate per setup
+_RECOVERY_CODE_COUNT = 10
+# Alphabet for each 4-character segment: lowercase letters + digits, no ambiguous chars
+_CODE_ALPHABET = string.ascii_lowercase + string.digits
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _generate_recovery_code() -> str:
+    """Return a single recovery code in ``xxxx-xxxx`` format."""
+    segment = lambda: "".join(secrets.choice(_CODE_ALPHABET) for _ in range(4))  # noqa: E731
+    return f"{segment()}-{segment()}"
+
+
+def _verify_totp_code(secret: str, code: str) -> bool:
+    """Verify a 6-digit TOTP code against the given base-32 secret (±1 window)."""
+    return pyotp.TOTP(secret).verify(code, valid_window=1)
+
+
+def _delete_recovery_codes(db: Session, *, user_id: int) -> None:
+    """Delete ALL recovery codes for a user (called on setup re-run and disable)."""
+    db.execute(delete(RecoveryCode).where(RecoveryCode.user_id == user_id))
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def setup(
+    db: Session,
+    *,
+    user: AuthUser,
+    issuer: str,
+) -> tuple[str, str, list[str]]:
+    """Generate a new pending TOTP secret and recovery codes.
+
+    The secret is stored in ``user.totp_secret`` (``totp_enabled`` stays
+    ``False``).  Any pre-existing pending secret and recovery codes are
+    replaced atomically.
+
+    Returns
+    -------
+    (secret, otpauth_uri, plaintext_recovery_codes)
+
+    ``plaintext_recovery_codes`` are returned **once** here and MUST NOT be
+    stored or returned elsewhere.
+    """
+    # Generate new TOTP secret
+    new_secret = pyotp.random_base32()
+    otpauth_uri = pyotp.TOTP(new_secret).provisioning_uri(
+        name=user.username,
+        issuer_name=issuer,
+    )
+
+    # Generate plaintext recovery codes
+    plaintext_codes = [_generate_recovery_code() for _ in range(_RECOVERY_CODE_COUNT)]
+
+    # --- Persist atomically ---
+    # 1. Delete any old pending recovery codes (idempotent on re-setup)
+    assert user.id is not None  # mypy guard; always set after DB insertion
+    _delete_recovery_codes(db, user_id=user.id)
+
+    # 2. Update the secret (pending — totp_enabled stays False)
+    user.totp_secret = new_secret
+
+    # 3. Persist new recovery codes as Argon2 hashes
+    for plaintext in plaintext_codes:
+        db.add(RecoveryCode(user_id=user.id, code_hash=hash_password(plaintext)))
+
+    db.commit()
+    db.refresh(user)
+
+    logger.info("TOTP setup (pending) for user '%s'; %d recovery codes generated.", user.username, _RECOVERY_CODE_COUNT)
+    return new_secret, otpauth_uri, plaintext_codes
+
+
+def enable(db: Session, *, user: AuthUser, code: str) -> bool:
+    """Enable TOTP after the user proves they can generate the correct code.
+
+    Parameters
+    ----------
+    code:
+        The current 6-digit TOTP code from the user's authenticator app.
+
+    Returns
+    -------
+    True on success; False if the code is invalid or no secret is pending.
+    """
+    if not user.totp_secret:
+        logger.info("TOTP enable rejected for '%s': no pending secret.", user.username)
+        return False
+
+    if not _verify_totp_code(user.totp_secret, code):
+        logger.info("TOTP enable rejected for '%s': wrong code.", user.username)
+        return False
+
+    user.totp_enabled = True
+    db.commit()
+    db.refresh(user)
+    logger.info("TOTP enabled for user '%s'.", user.username)
+    return True
+
+
+def disable(
+    db: Session,
+    *,
+    user: AuthUser,
+    password: str | None = None,
+    code: str | None = None,
+) -> bool:
+    """Disable TOTP.  Caller must supply exactly one of ``password`` or ``code``.
+
+    On success: ``totp_enabled=False``, ``totp_secret=None``, all recovery
+    codes deleted.
+
+    Returns
+    -------
+    True on success; False if neither credential is valid.
+    """
+    if not password and not code:
+        logger.info("TOTP disable rejected for '%s': no credential provided.", user.username)
+        return False
+
+    if password:
+        if not verify_password(password, user.password_hash):
+            logger.info("TOTP disable rejected for '%s': wrong password.", user.username)
+            return False
+    elif code:
+        if not user.totp_secret or not _verify_totp_code(user.totp_secret, code):
+            logger.info("TOTP disable rejected for '%s': wrong TOTP code.", user.username)
+            return False
+
+    # Clear TOTP state
+    assert user.id is not None
+    _delete_recovery_codes(db, user_id=user.id)
+    user.totp_enabled = False
+    user.totp_secret = None
+    db.commit()
+    db.refresh(user)
+    logger.info("TOTP disabled for user '%s'.", user.username)
+    return True
+
+
+def verify_totp_code(user: AuthUser, code: str) -> bool:
+    """Verify a 6-digit TOTP code for a user.
+
+    Returns True if the code is valid (±1 time window), False otherwise.
+    The user must have a ``totp_secret`` set; returns False if not.
+
+    This is the public entry-point for T06 login two-factor verification.
+    """
+    if not user.totp_secret:
+        return False
+    return _verify_totp_code(user.totp_secret, code)
+
+
+def verify_recovery_code(db: Session, *, user: AuthUser, code: str) -> bool:
+    """Verify and consume a one-time recovery code.
+
+    Finds the first unused recovery code whose hash matches ``code``, marks it
+    as consumed (sets ``used_at``), and returns ``True``.  Returns ``False`` if
+    no matching unused code exists.
+
+    This function is provided for T06 (login two-factor) but lives here so the
+    TOTP service owns all recovery-code logic.
+    """
+    from datetime import UTC, datetime
+
+    unused = db.execute(
+        select(RecoveryCode).where(
+            RecoveryCode.user_id == user.id,
+            RecoveryCode.used_at.is_(None),
+        )
+    ).scalars().all()
+
+    for rc in unused:
+        if verify_password(code, rc.code_hash):
+            rc.used_at = datetime.now(UTC)
+            db.commit()
+            logger.info(
+                "Recovery code consumed for user '%s' (id=%d).", user.username, rc.id
+            )
+            return True
+
+    return False
@@ -62,6 +62,8 @@ packaging==26.1
    #   build
    #   pytest
    #   wheel
+paho-mqtt==2.1.0
+    # via -r requirements.in
 pip-tools==7.5.3
    # via -r dev-requirements.in
 pluggy==1.6.0
@@ -78,6 +80,10 @@ pydantic-settings==2.13.1
    # via -r requirements.in
 pygments==2.20.0
    # via pytest
+pymodbus==3.13.1
+    # via -r requirements.in
+pyotp==2.10.0
+    # via -r requirements.in
 pyproject-hooks==1.2.0
    # via
    #   build
@@ -20,9 +20,9 @@ services:
    build: .
    image: home-automation:dev
    container_name: home-automation-app-dev
-    # Publish on 8001 for dev. `!override` REPLACES the base ports list instead of
+    # Publish on 8002 for dev. `!override` REPLACES the base ports list instead of
    # appending to it, so the dev stack does NOT also bind the production 8881.
    ports: !override
-      - "127.0.0.1:8001:8000"
+      - "127.0.0.1:8002:8000"
    environment:
      APP_DATABASE_URL: "sqlite:////app/data/app.db"
@@ -9,6 +9,7 @@ services:
    volumes:
      - ./data:/app/data
      - ./.env:/app/.env:ro
+      - /etc/localtime:/etc/localtime:ro

  app:
    container_name: home-automation-app
@@ -24,4 +25,5 @@ services:
    volumes:
      - ./data:/app/data
      - ./.env:/app/.env:ro
+      - /etc/localtime:/etc/localtime:ro

@@ -19,31 +19,42 @@

 - `main.py`
  - FastAPI app factory
-  - lifespan
+  - lifespan（APScheduler 启停、MQTT 客户端起停、连接后触发 HA Discovery 发布；M6 新增 `tibber-refresh` 抓价 job + `energy-cost` 1 分钟计费 tick job；M6 启用时注册 DSMR MQTT 订阅）
  - 基础路由注册
 - `config.py`
-  - 环境变量驱动的 settings
+  - 环境变量驱动的 settings（含 M5 新增的 MQTT/HA Discovery/Modbus 配置项；M6 新增 `dsmr_ingest_enabled`、`dsmr_mqtt_topic`、`dsmr_sample_interval_s`、`tibber_api_token`（secret）、`tibber_home_id`）
 - `db.py`
  - 统一数据层：一个 `Base`、一个绑定 `app_database_url` 的 cached engine（SQLite WAL）、`get_engine` / `get_session_local` / `reset_db_caches` / `get_db_session`
 - `dependencies.py`
  - 通用依赖注入
 - `api/`
  - HTTP routes
-  - `api/routes/api/`：JSON API（`/api/*` 前缀），供 React SPA 调用：会话/鉴权、配置读写、数据查询、记录 CRUD
+  - `api/routes/api/`：JSON API（`/api/*` 前缀），供 React SPA 调用：会话/鉴权、配置读写、数据查询、记录 CRUD、Modbus 设备 CRUD + readings + metrics + test（`/api/modbus/*`）、Expose 勾选 + 重发 discovery（`/api/expose`）、MQTT 测试连接（`/api/config/mqtt/test`）、M6 新增合同 CRUD + 版本（`/api/energy/contracts*`）、pricing profile 列表（`/api/energy/profiles`）、价格/费用/汇总/DSMR 最新/重算/Tibber 测试（`/api/energy/prices`、`/api/energy/costs`、`/api/energy/costs/summary`、`/api/energy/dsmr/latest`、`/api/energy/costs/recompute`、`/api/energy/tibber/test`）
  - 裸 ingestion 端点：`GET /public-ip/check`、`POST /homeassistant/publish`、`POST /poo/record`、`GET /poo/latest`、TickTick OAuth 等
 - `models/`
  - SQLAlchemy models
-  - 所有模型（auth / config / public_ip / location / poo）共用同一个 `Base`，均落在单一 `app.db` 中
+  - 所有模型（auth / config / public_ip / location / poo / modbus / expose / energy）共用同一个 `Base`，均落在单一 `app.db` 中
+  - M5 新增：`ModbusDevice`（设备部署层）、`ModbusReading`（通用遥测，JSON payload）、`ExposedEntityToggle`（HA 实体暴露开关）
+  - M6 新增：`DsmrReading`（整帧 DSMR telegram，10s 降采样）、`EnergyContract`（合同头，含 active 标记）、`EnergyContractVersion`（版本/时段，values JSON，只增不改）、`TibberPrice`（15 分钟价缓存，不可变）、`EnergyCostPeriod`（每 15 分钟计量电费，快照价，不可变）
 - `schemas/`
-  - Pydantic schemas
+  - Pydantic schemas（M5 新增 `modbus.py`、`expose.py`；M6 新增 `energy_contract.py`、`energy.py`）
 - `services/`
  - 业务服务层
  - 当前已迁入 config page 的 DB 持久化逻辑
  - 当前已迁入 public IPv4 检查、状态持久化与变化通知逻辑
  - 当前已迁入 SMTP 发信与测试发信逻辑
+  - M5 新增：`modbus_poll.py`（采集 service，逐设备 poll + 落库 + 推 MQTT state）、`ha_discovery.py`（构建 HA Discovery payload、发布 retained config、发布 state）
+  - M6 新增：`tibber_prices.py`（httpx GraphQL 抓 15 分钟价，upsert `tibber_price`，幂等；仅 active=tibber 且 token 存在时运行）、`dsmr_ingest.py`（MQTT handler，整帧 JSON blob + 10s 降采样落库，`source_id` 幂等）、`energy_cost.py`（计费引擎：每 15 分钟寄存器差 × strategy 出价 → `energy_cost_period` 不可变快照；汇总 Σnet + 固定费 − heffingskorting；重算显式 opt-in）
 - `integrations/`
  - 外部系统适配层
-  - 当前已迁入 Home Assistant outbound adapter
+  - Home Assistant outbound adapter（REST 通道，原有）
+  - M5 新增：`modbus/`（pymodbus 薄封装：`driver.py` 块读 + float32 解码；`profiles.py` YAML profile 加载/校验/解码；`profiles/sdm120.yaml` SDM120 协议声明）
+  - M5 新增：`mqtt.py`（paho-mqtt 长连接 `MqttManager`：lifespan 起/停、配置变更重连、`publish(topic, payload, retain)`）
+  - M5 新增：`expose.py`（通用 expose 框架：`ExposableEntity`、provider 注册表、`build_catalog`；Modbus provider 从 YAML profile 派生 sensor/binary_sensor 实体目录）
+  - M6 新增：`pricing/`（通用电价层：`profiles.py` pydantic 加载/校验 YAML profile + `validate_values`；`strategies.py` manual/tibber 出价策略注册表；`profiles/manual.yaml` 固定/双费率结构；`profiles/tibber.yaml` 动态电价结构）
+  - M6 新增：`tibber/`（`client.py`：httpx GraphQL 客户端，`priceInfoRange(QUARTER_HOURLY)` 查询，按 `starts_at` 解析，不假设固定节点数）
+  - M6 扩展：`mqtt.py` 新增订阅端（`subscribe(topic, handler)`，`on_connect` 里 subscribe，`on_message` 按 topic 分发，handler 异常吞掉不崩连接）
+  - M6 扩展：`expose.py` 新增 `_energy_cost_provider`（`buy_price_now`、`sell_price_now`、`import_cost_total`/`export_revenue_total` 均 `total_increasing`，反哺 HA Energy）
 - `static/`
  - 极简静态资源

@@ -69,18 +80,94 @@ React SPA 前端（M2 引入）。Vite + React + TypeScript + Mantine，由 Fast

 ### `scripts/`

-辅助脚本目录。当前包含 OpenAPI 导出脚本（`export_openapi.py`）与数据层辅助脚本。
+辅助脚本目录。当前包含：
+
+- `export_openapi.py`：导出 OpenAPI schema 静态产物
+- `run_migrations.py`：运行 Alembic migration
+- `app_db_adopt.py`：App DB 接管 / 初始化
+- `migrate_legacy_data.py`：一次性历史数据搬迁脚本
+- `admin_cli.py`：Admin CLI 逃生通道（M4），见下方"登录加固"说明
+- `modbus_cli.py`（M5）：Modbus 手工试读 CLI（`read`/`probe` 两个只读子命令），不依赖 DB，供受控手工验证链路连通性

 ### `openapi/`

 OpenAPI schema 静态产物（`openapi.json` / `openapi.yaml`），由 `python scripts/export_openapi.py` 生成，纳入版本控制。前端 codegen 以此为契约源。

+## 登录加固（M4）
+
+M4 在基础 Argon2 + server-side session 鉴权之上叠加了三层防御：
+
+**防爆破 / 指数退避**：`app/services/login_throttle.py` 按 client IP 与 username 双键记失败计数，失败超过 3 次后指数增长等待时间（最长 15 分钟），`POST /api/auth/login` 在退避窗口内直接返回 `429 + Retry-After`，不执行 Argon2 验证。成功登录后清零。退避是延迟而非永久封号；全局开关 `AUTH_LOGIN_THROTTLE_ENABLED`（CONFIG_FIELDS，默认开）；反代后需设 `AUTH_TRUST_FORWARDED_FOR=true`（`.env` 部署级，默认 false）。
+
+**CLI 逃生通道**：`scripts/admin_cli.py`（入口 `python -m scripts.admin_cli`）直连本地 DB，**无需 HTTP 服务运行、无需任何已存凭据**，支持：重置密码（`reset-password`）、解锁退避（`unlock`）、关停 TOTP（`disable-totp`，零凭据最终逃生）、重新发放 TOTP secret（`reissue-totp`）、查看用户列表（`list-admin`）。CLI 只动 auth 行，不触碰用户数据表。
+
+**可选 TOTP 二次验证**：admin 可在设置页自选启用 RFC 6238 TOTP。启用后登录为两步（密码 → 6 位动态码或一次性恢复码）；不启用维持纯密码。TOTP secret 明文存库（与其他 secret 一致，靠文件权限保护）；恢复码以 Argon2 哈希存储，使用后消费（一次性）。后端使用 `pyotp`，二维码由前端 `qrcode.react` 渲染。issuer 标签由 `AUTH_TOTP_ISSUER`（`.env` 部署级）配置，默认回退 `app_name`。
+
+详细说明：[`docs/auth.md`](./auth.md)
+
+## M5 — 通用 Modbus 采集链路与 MQTT 通道
+
+### Modbus 采集链路
+
+```
+YAML profile（协议知识）         modbus_device 行（部署信息，DB）
+  - 寄存器块/地址/类型             - host / port（网关 IP）
+  - 每量：key/unit/device_class    - unit_id（Modbus slave 地址）
+  - ha_component                   - friendly_name / profile / poll_interval_s / enabled
+          │                                    │
+          └────────────┬───────────────────────┘
+                       │ APScheduler job（轮询所有 enabled 设备）
+                       │  driver.py: ModbusTcpClient → FC04 块读 → 大端 float32 解码
+                       │  profiles.py: decode(profile, registers) → dict[key → value]
+                       ▼
+              modbus_reading 行
+              device_id · recorded_at · payload(JSON)
+              {"voltage": 230.2, "current": 1.3, "active_power": 295.0, ...}
+```
+
+**关键设计决策**：
+- 命名分层：存储/采集/API 全部通用 `modbus_*`（`/api/modbus/devices`）；面向用户的领域视图叫 **Energy**（第一个）。接入新设备型号只需新增 YAML profile，不改表/不改 API。
+- 读数为 JSON `payload`（无固定列），SQLite `json_extract` 在 DB 端做 AVG/GROUP BY（被 `(device_id, recorded_at)` 索引圈住）。
+- FK `ON DELETE RESTRICT`：有读数的设备拒删，引导改为 `enabled=false`。
+- 设备 `uuid`（uuid4 内部生成）是**稳定身份锚点**：API 路径键、HA Discovery `unique_id` 来源，不随 friendly_name 改变。
+
+### 第二条 MQTT 通道（HA Discovery 发布）
+
+与已有 REST 通道（`app/integrations/homeassistant.py`、`POST /homeassistant/publish`）**并行、不冲突**：
+
+```
+MQTT 通道（M5 新增）：
+  paho-mqtt MqttManager（lifespan 长连接，配置变更可重连）
+        │
+        ├─► Discovery config（retained）
+        │     topic: <prefix>/<component>/<node>/<object>/config
+        │     内容：device 块（identifiers=uuid）、state_topic、unique_id（uuid+key）、
+        │           name（friendly_name）、device_class、unit_of_measurement、availability
+        │     时机：连接成功时 / 目录或勾选变更时（全量重发）；
+        │           取消勾选时发空 payload（清除 entity）
+        │
+        └─► State / Availability（非 retained）
+              时机：每次轮询成功后推该设备所有 enabled entity 的最新值；
+                    周期兜底 job 重推所有 enabled entity + online topic
+
+expose 框架：
+  provider 动态产出 ExposableEntity 目录（元数据从 YAML profile 派生）
+  ExposedEntityToggle 表：只存逐 key 开关（default=disabled）
+  build_catalog(session) → 目录 + 勾选状态（合并所有 provider）
+```
+
+**HA entity 身份模型（Z2M 语义）**：
+- `unique_id` = `f"{device.uuid}_{metric.key}"`（稳定，改名不变）
+- `name` = `friendly_name`（改名重发 discovery，HA 显示名跟着变、历史不丢）
+- 每设备除各 sensor entity 外，另有 `binary_sensor` `online`（取 `last_poll_ok`）——这是"不止 sensor"的体现
+
 ## 当前约束

 - 当前数据库继续使用 SQLite
 - ~~当前不引入前后端分离~~ **已退役（M2）**：现为 React SPA + JSON `/api` 层，由 FastAPI 同源托管
 - 当前不设计 Notion 模块
 - 当前通知能力仍保持极小范围，不引入独立通知中心或多渠道抽象
+- Modbus 当前**仅 TCP**（Waveshare RTU↔TCP 网关），**只读**（FC03/04），不写设备寄存器

 ## 关于 Notion

@@ -1,120 +1,229 @@
-# 基础鉴权说明
+# 鉴权说明

-本文档说明当前 Python 重构项目里已经落地的第一版鉴权基座。
-
-这一轮只解决：
-
- 登录页
- 登录 / 登出流程
- server-side session
- 一个最小受保护页面
-
-这一轮明确不解决：
-
- 完整 config persistence
- 完整 config CRUD
- 多用户权限系统
- OAuth / SSO / RBAC
+本文档说明当前已落地的鉴权基座（基础 session 鉴权 + M4 登录加固）。

 ## 当前 auth 模型

- 认证方式：`username/password`
+- 认证方式：`username/password`（可选启用 TOTP 二次验证）
 - 会话方式：server-side session
 - 客户端凭据：session cookie
- 页面形态：Jinja server-side template

-## 当前持久化
+## 持久化

-当前新增一个共享 App DB：
+所有 auth 相关数据存放在单一 App DB（`APP_DATABASE_URL`，默认 `sqlite:///./data/app.db`）中：

- `APP_DATABASE_URL`
- 默认值：`sqlite:///./data/app.db`
-
-当前 auth 相关数据存放在这个 DB 中：
-
- `auth_users`
- `auth_sessions`
- `app_config`
-
-当前没有把 auth 数据和 `location` / `poo` DB 混放。
-
-当前这部分现在也走 Alembic 管理：
-
- Alembic 环境：`alembic_app.ini` + `alembic_app/`
- 初始化脚本：`python scripts/app_db_adopt.py`
-
-当前没有 legacy app DB，所以这一版脚本只负责初始化新库，不负责 legacy adoption。
-
-`app_config` 现在承接运行时配置持久化。
-
-其中：
-
- `.env` 负责 bootstrap / fallback
- `app_config` 表负责运行时配置覆盖
- 登录密码仍然属于认证数据，使用 Argon2 哈希，不存进 `app_config`
+- `auth_users`：用户表（含 TOTP 字段 `totp_secret` / `totp_enabled`）
+- `auth_sessions`：session token 哈希与过期时间
+- `auth_login_throttle`：登录失败退避状态（按 IP / username 双键）
+- `auth_recovery_code`：TOTP 恢复码哈希（一次性）
+- `app_config`：runtime 配置持久化

 ## 首次启动与 bootstrap

-如果 auth DB 中还没有任何用户，应用启动时会要求：
+如果 auth DB 中还没有任何用户，应用启动时会使用：

 - `AUTH_BOOTSTRAP_USERNAME`
 - `AUTH_BOOTSTRAP_PASSWORD`

-并创建首个 admin 用户。
-
-当前默认 bootstrap 值就是：
+创建首个 admin 用户。当前默认 bootstrap 值为：

 - username: `admin`
 - password: `admin`

 首次登录后，系统会强制要求修改密码。

-如果你希望在首次启动前就覆盖默认值，可以直接设置环境变量：
+## 基础安全设计

- `AUTH_BOOTSTRAP_USERNAME`
- `AUTH_BOOTSTRAP_PASSWORD`
-
-建议流程是：
-
-1. 配好 `.env`
-2. 运行 `python scripts/app_db_adopt.py`
-3. 启动应用
-4. 用 `admin / admin` 首次登录
-5. 立即修改密码
-
-## 安全设计
-
-当前这版已经落实的基础安全点：
+当前这版已经落实的安全点：

 - 密码不明文存储，使用 Argon2 哈希
 - session cookie 为 `HttpOnly`
 - cookie 使用 `SameSite=Lax`
 - `Secure` cookie 在非 `development` 环境默认开启
- 登录表单与登出表单都有基础 CSRF 校验
+- 写请求（POST/PUT/PATCH/DELETE）需携带 `X-CSRF-Token` header（SameSite=Lax + 自定义 header 纵深防御，无需 per-session token 值比对）
 - session token 为随机生成，服务端只持久化 token hash
- session 有过期时间与显式失效机制
+- session 有过期时间（默认 12 小时）与显式失效机制

-## 当前受保护范围
+---

-当前这轮只保护了页面入口：
+## M4 登录加固

- `GET /config`
- `POST /config`
- `POST /config/change-password`
- `POST /logout`
+M4 在基础鉴权之上叠加了三层防御：防爆破/指数退避、CLI 逃生通道、可选 TOTP 二次验证。

-相关流程：
+### 1. 防爆破 / 指数退避

- `GET /login`
- `POST /login`
+#### 机制

-未登录访问 `/config` 时会被重定向到 `/login`。
+登录失败按指数增长延迟，目标是拖垮暴力枚举，同时不因此永久锁定账号。

-## 下一步不在本轮内
+**退避是延迟（429 + Retry-After），不是永久封号**——单 admin 场景下永久锁会被攻击者反向用来故意打锁，所以退避只增加等待时间，CLI 是最终逃生口。

-后续可以在这个基座上继续做：
+#### 双键计算

- 配置页面接入
- config persistence
- 更细的受保护路由范围
- 用户初始化 / 密码轮换的更正式 runbook
+每次登录请求同时按 **client IP** 和 **username** 各记一套失败计数，本次需等待时间 = 两者退避的**较大值**。
+
+- 按 IP：堵单点暴力（攻击 IP 越敲越慢，合法用户换 IP 不受影响）
+- 按 username：全局兜底（即便攻击者分布式换 IP 也有一层保护）
+
+#### 指数公式
+
+```
+N_FREE  = 3       — 前 3 次失败不延迟（免费次数）
+BASE    = 1  秒
+CAP     = 900 秒（15 分钟）
+
+wait = min(CAP, BASE × 2^(failures - N_FREE))   （failures > N_FREE 时生效）
+```
+
+延迟示意：
+
+| 累计失败次数 | 等待时间 |
+| --- | --- |
+| 1–3 | 0 秒（免费） |
+| 4 | 2 秒 |
+| 5 | 4 秒 |
+| 6 | 8 秒 |
+| 7 | 16 秒 |
+| … | … |
+| 13+ | 900 秒（封顶） |
+
+成功登录后，该 IP 和 username 的退避状态**立即清零**。
+
+#### 登录端点行为（`POST /api/auth/login`）
+
+1. 先查退避（在窗口内直接 `429`，**不验密码**，节省 Argon2 计算并防止枚举）
+2. 验密码失败 → 记一次失败（IP + username 各记），返回 `401`
+3. 密码正确但 TOTP 启用且缺少 `totp_code` → 返回 `401 {totp_required: true}`，**不记失败**（这是正常两步流程的第一步，不是攻击信号）
+4. 密码正确但 TOTP 验证失败 → 记一次失败，返回 `401`
+5. 全部通过 → 清零退避状态，发 session cookie
+
+#### 配置项
+
+| 配置项 | 类型 | 默认 | 说明 |
+| --- | --- | --- | --- |
+| `AUTH_LOGIN_THROTTLE_ENABLED` | bool（CONFIG_FIELDS） | `true` | 全局开关，关闭后整个退避机制 no-op |
+| `AUTH_TRUST_FORWARDED_FOR` | bool（`.env` 部署级） | `false` | `true` 时取 `X-Forwarded-For` 最左作为 client IP；**反代后必须显式开启**，否则反代 IP 全视为同一 IP，按 IP 退避失效 |
+
+> **反代部署注意**：`AUTH_TRUST_FORWARDED_FOR` 默认 `false`（直接用 socket IP）。部署在 nginx 等反代后面时，应设 `AUTH_TRUST_FORWARDED_FOR=true`，并确保反代正确设置 `X-Forwarded-For`。
+
+---
+
+### 2. CLI 逃生通道
+
+#### 设计原则
+
+CLI 通过 **直连本地 DB**（`get_session_local()`）工作，**无需 HTTP 服务器运行、无需任何已存凭据**（密码、恢复码均不需要）。拿到服务器 CLI 权限本身就意味着对系统有完全控制，因此这是可接受且必须存在的最终逃生口。
+
+CLI 只动 auth 相关行（`auth_users` 的密码/TOTP 字段、`auth_login_throttle`、`auth_recovery_code`），**绝不**触碰用户数据表（`location`、`poo_records`、`public_ip_state` 等）。
+
+入口：`python -m scripts.admin_cli <command>`
+
+#### 子命令
+
+| 命令 | 用途 | 逃生场景 |
+| --- | --- | --- |
+| `reset-password <username> [--password <pwd>]` | 重置密码（不带 `--password` 则交互式输入，不回显） | 忘记密码 |
+| `unlock [--all \| --ip <ip> \| --username <u>]` | 清 `auth_login_throttle` 行 | 被退避锁住（429）时解锁 |
+| `disable-totp <username>` | 关停 TOTP（清 secret + 删全部恢复码），**零凭据可执行** | 恢复码全丢也能进 |
+| `reissue-totp <username>` | 生成新 TOTP secret 并打印 `otpauth://` URI | 设备丢失、需重新注册 Authenticator |
+| `list-admin` | 列出所有用户与状态列 | 排障用 |
+
+#### 使用示例
+
+```bash
+# 重置密码（不带 --password 时交互式 prompt，不回显）
+python -m scripts.admin_cli reset-password admin
+
+# 重置密码（非交互，脚本里用）
+python -m scripts.admin_cli reset-password admin --password "newpassword"
+
+# 解锁所有退避
+python -m scripts.admin_cli unlock --all
+
+# 解锁特定 IP
+python -m scripts.admin_cli unlock --ip 1.2.3.4
+
+# 解锁特定 username
+python -m scripts.admin_cli unlock --username admin
+
+# 关停 TOTP（零凭据，最终逃生口）
+python -m scripts.admin_cli disable-totp admin
+
+# 重新发放 TOTP secret（打印新 otpauth:// URI，扫码重新注册）
+python -m scripts.admin_cli reissue-totp admin
+
+# 查看用户列表
+python -m scripts.admin_cli list-admin
+```
+
+在 Docker 容器内执行：
+
+```bash
+docker compose exec app python -m scripts.admin_cli <command>
+```
+
+#### `reissue-totp` 语义说明
+
+- 对**已启用** TOTP 的用户：新 secret **立即在登录时生效**，旧 Authenticator 生成的码立即失效；**无需**再走 web `enable` 步骤。
+- 现有恢复码**不被删除**——恢复码是独立的随机哈希值，与 TOTP secret 无密码学绑定，reissue 后恢复码依然有效（仍可用于登录）。
+- 如果需要完整清理（secret + 所有恢复码），使用 `disable-totp`。
+
+---
+
+### 3. 可选 TOTP 二次验证
+
+#### 设计
+
+- TOTP 遵循 RFC 6238，使用 `pyotp` 库。
+- 二维码在**前端**由 `qrcode.react` 渲染（后端只返回 `otpauth://` URI，不引图像依赖）。
+- `totp_secret` 明文存库（与项目其他 secret 处理一致，靠数据库文件权限保护）。
+- 恢复码以 Argon2 哈希存库，一次性（使用后标记 `used_at`）。
+
+#### 启用流程
+
+1. **setup**（`POST /api/auth/totp/setup`）：生成 pending secret，返回 secret、`otpauth://` URI、10 个明文恢复码（**仅此一次**）；此时 `totp_enabled` 仍为 `false`。
+2. **扫码**：用 Authenticator App 扫前端渲染的二维码（或手动输入 secret）。
+3. **enable**（`POST /api/auth/totp/enable`）：输入当前 6 位码确认 → `totp_enabled` 变为 `true`。
+4. 妥善保存恢复码（不会再次展示）。
+
+#### 停用流程
+
+**web 停用**（`POST /api/auth/totp/disable`）：需提供当前密码或当前 6 位 TOTP 码。成功后清 secret、删全部恢复码，恢复纯密码登录。
+
+**CLI 停用**（逃生口，恢复码全丢时）：`python -m scripts.admin_cli disable-totp admin`，零凭据，立即生效。
+
+#### 登录二步流程
+
+1. 提交 `POST /api/auth/login {username, password}` → 密码正确但 TOTP 已启用 → `401 {totp_required: true}`（不发 session）
+2. 前端切到第二屏，提交 `POST /api/auth/login {username, password, totp_code}` → 通过 → 发 session cookie
+
+`totp_code` 可以是 6 位 TOTP 动态码，也可以是 `xxxx-xxxx` 格式恢复码（命中即消费，不可复用）。
+
+#### API 端点
+
+| 端点 | 用途 |
+| --- | --- |
+| `POST /api/auth/totp/setup` | 生成 pending secret + URI + 恢复码（一次性明文返回） |
+| `POST /api/auth/totp/enable` | 带当前 6 位码确认启用 |
+| `POST /api/auth/totp/disable` | 带密码或当前码停用 |
+| `GET /api/auth/totp` | 返回当前 TOTP 状态（`{enabled: bool}`），不返回 secret/恢复码 |
+
+全部端点需要 session cookie（`GET /api/auth/totp` 不需 CSRF；其余写端点需 `X-CSRF-Token`）。
+
+#### 配置项
+
+| 配置项 | 类型 | 默认 | 说明 |
+| --- | --- | --- | --- |
+| `AUTH_TOTP_ISSUER` | str（`.env` 部署级） | 空（回退 `app_name`） | 显示在 Authenticator App 里的 issuer 标签 |
+
+---
+
+## 受保护范围
+
+当前 JSON API 端点（`/api/*`）需要 session cookie；写端点需额外携带 `X-CSRF-Token` header。
+
+裸 ingestion 端点（`/location/record`、`/poo/record` 等设备调用端点）暂未收口到 session 保护（M3 计划引入 token 鉴权）。
+
+## 下一步（不在当前范围）
+
+- M3：token 鉴权（供脚本 / 设备 / 移动端调用 API），ingestion 端点收口。
@@ -1,12 +1,16 @@
 # 设计文档与多模型协作约定

-本目录把 `docs/roadmap.md` 里的三个里程碑展开成**可被 coding agent 流水线执行**的详细设计文档。
+本目录把 `docs/roadmap.md` 里的各个里程碑展开成**可被 coding agent 流水线执行**的详细设计文档。

 - [`m1-db-consolidation.md`](./m1-db-consolidation.md) — 单库化地基
 - [`m2-frontend-v2.md`](./m2-frontend-v2.md) — React SPA 前端 v2
 - [`m3-token-mobile.md`](./m3-token-mobile.md) — token 鉴权与移动端（远期）
+- [`m4-login-hardening.md`](./m4-login-hardening.md) — 登录加固（防爆破/指数退避 + CLI 逃生 + 可选 TOTP）**先做**
+- [`m5-iot-energy.md`](./m5-iot-energy.md) — IoT 集成与能耗采集（Modbus/Energy + MQTT/HA Discovery + 前端侧边栏）
+- [`m6-tibber-dynamic-energy.md`](./m6-tibber-dynamic-energy.md) — 通用电价层 + DSMR 实时电表接入 + 实时买卖电费计算 + HA Energy 反哺
+- [`m7-meter-epochs-archival.md`](./m7-meter-epochs-archival.md) — 电表生命周期 / 换表归档（Meter epochs）

-本文件定义**所有任务共用的格式与协作规则**，三个里程碑文档不再重复这些约定。
+本文件定义**所有任务共用的格式与协作规则**，各个里程碑文档不再重复这些约定。

 ---

@@ -0,0 +1,309 @@
+# M4 — 登录加固（Login Hardening）
+
+> 阅读前提：先读 [`README.md`](./README.md)（协作模型、任务卡格式、校验闸门、数据安全红线）。
+> **排期：本里程碑排在 [M5](./m5-iot-energy.md) 之前。** 系统现为公网 + 仅密码 + 无限重试，是现成风险；M4 与 M5 零文件重叠，先堵这个洞再做 IoT。
+
+## 1. 目标
+
+给暴露在公网的单 admin 登录做纵深防御：
+
+1. **防爆破 / 指数退避**：失败登录按指数增长延迟，拖垮暴力枚举；成功即清零。
+2. **CLI 逃生通道**：纯命令行重置密码 / 解锁 / 关停 TOTP，**不依赖任何已存恢复凭据**——拿到服务器 CLI 权限的人本来就无所不能，所以这是可接受、且必须存在的最终逃生口（消除"锁死就彻底进不去"的死角）。
+3. **TOTP 二次验证（可选配）**：admin 可**自选启用** RFC 6238 TOTP；启用后登录需密码 + 6 位动态码；提供一次性恢复码；CLI 能在恢复码全丢时关掉 TOTP。**非强制**，不启用则维持纯密码登录。
+
+> 三段顺序：A（防爆破，紧急、可独立先发版）→ B（TOTP，可选配）→ 收尾。Phase A 自成可用增量，Phase B 失败不影响 A。
+
+## 2. 现状（实现者可据此工作，不必通读全仓库）
+
+**单 admin + Argon2**
+- `app/models/auth.py`：`AuthUser`（`id / username unique / password_hash / is_active / force_password_change / created_at`）、`AuthSession`（`token_hash / csrf_token / expires_at / revoked_at`）。单库 `Base`。
+- `app/services/auth.py`：
+  - `authenticate_user(session, *, username, password) -> AuthUser | None`：查用户→`verify_password`（Argon2）；失败只 `logger.info`，**无任何节流**。
+  - `create_session(session, *, user, settings) -> (AuthSession, raw_token)`：`secrets.token_urlsafe`，SHA256 存 `token_hash`，TTL `auth_session_ttl_hours`（默认 12h）。
+  - `change_password(...)`、`get_authenticated_session(...)`、`initialize_auth_schema(session, settings)`（**仅当无任何用户时**用 `AUTH_BOOTSTRAP_USERNAME/PASSWORD` 建初始 admin）。
+- `app/api/routes/api/session.py`：
+  - `POST /api/auth/login`（body `{username, password}`）：`authenticate_user` → None 则 401；否则 `create_session` + `set_cookie`(HttpOnly/SameSite=Lax/`auth_cookie_secure`) → 返回 `{user, csrf_token}`。
+  - `GET /api/session`（401 或 user+csrf）、`POST /api/auth/logout`（CSRF）、`POST /api/auth/password`（CSRF + 校验当前密码）。
+
+**配置**
+- `app/config.py`：`auth_bootstrap_username/password`、`auth_session_cookie_name`、`auth_session_ttl_hours`、`auth_cookie_secure_override`（computed `auth_cookie_secure`）。
+- 配置系统：扁平 KV（`CONFIG_FIELDS` 注册表 + `Settings` + `_settings_payload`），新增标量配置项前端自动渲染（见 M5 文档 §2）。
+
+**无现成 CLI**
+- `scripts/`：`run_migrations.py` / `app_db_adopt.py` / `migrate_legacy_data.py`(argparse) / `export_openapi.py`。**没有**任何 admin/密码/auth 的 CLI。
+- `pyproject.toml`：**无 `console_scripts`**。CLI 入口沿用 `python -m scripts.<mod>` 风格（与 `python -m scripts.run_migrations` 一致）。
+
+**前端登录（单步）**
+- `frontend/src/pages/LoginPage.tsx`：`POST /api/auth/login {username,password}` → 401 显示通用错误；成功存 csrf、跳转。
+- `frontend/src/auth/SessionProvider.tsx`：`GET /api/session` 引导。
+- 无"锁定/稍后再试"提示、无二步流程。
+
+**测试**
+- `tests/test_api_session.py`（凭据/cookie/登出/改密/强制改密）；`tests/conftest.py` 用 env 设 bootstrap 凭据。
+
+## 3. 目标架构
+
+### 3.1 防爆破 / 指数退避
+
+- **状态表 `auth_login_throttle`**：按 key 记失败窗口（`key / scope / failures / first_failed_at / last_failed_at / next_allowed_at`），成功即删该 key 的行。
+- **双键**：同时按 **client IP** 与 **username** 计；本次请求需等待 = 两者退避的**较大值**。
+  - 按 IP：堵单点暴力（attacker IP 越敲越慢，合法用户换 IP 不受影响）。
+  - 按 username：单 admin 的全局兜底（即便分布式换 IP 也有一层）。
+  - **DoS 权衡**：单 admin 下纯按 username 硬锁会被攻击者故意失败把你锁死，所以退避是**延迟（429 + Retry-After）而非永久锁定**，且 CLI 是最终逃生口。
+- **client IP 来源**：默认用 socket IP；`AUTH_TRUST_FORWARDED_FOR=true` 时取 `X-Forwarded-For` 最左（部署在反代后才开）。**这点必须显式配置**，否则反代后所有请求同一 IP，按 IP 退避失效。
+- **指数公式（默认，常量可后调）**：前 `N_free=3` 次不延迟；之后 `wait = min(cap, base * 2^(failures - N_free))`，`base=1s`、`cap=900s`。
+- **接入点**：`POST /api/auth/login` 开头先查退避 → 在窗口内直接 429（带 `Retry-After`），**不验密码**（省 Argon2、防枚举）；验密码失败 → 记一次失败；成功 → 清该 IP + username 的退避行。
+- **全局开关** `AUTH_LOGIN_THROTTLE_ENABLED`（CONFIG_FIELDS，默认 true）。
+
+### 3.2 CLI 逃生通道
+
+`scripts/admin_cli.py`（`python -m scripts.admin_cli <cmd>`，argparse 子命令；直接连本地 DB，无网络，复用 `get_session_local()` + 模型 + Argon2 hasher）：
+
+| 命令 | 作用 |
+| --- | --- |
+| `reset-password <username> [--password ...]` | 重置密码（不给则交互式 prompt，不回显）；逃生：忘密码 |
+| `unlock [--all | --ip <ip> | --username <u>]` | 清 `auth_login_throttle` 行；逃生：被退避锁住 |
+| `disable-totp <username>` | 关 TOTP（清 secret + 恢复码）；逃生：**恢复码全丢也能进**（Phase B 才有意义）|
+| `reissue-totp <username>` | 重新发放 TOTP secret（可选）|
+| `list-admin` | 列用户/状态（排障）|
+
+- **数据安全**：CLI 只动 auth 状态行（人工执行的 admin 动作），**绝不**触碰用户数据表（location/poo/energy 等），不 drop 有数据的表。
+
+### 3.3 TOTP 二次验证（可选配）
+
+- **库**：`pyotp`（Python 侧）；二维码在**前端**用 JS 库（`qrcode.react`）从 `otpauth://` URI 渲染——后端不引图像依赖。
+- **存储**：
+  - `AuthUser` 增列 `totp_secret`(nullable)、`totp_enabled`(bool, default false)。secret 落库明文（与现有 secret 处理一致，靠文件权限保护；文档注明）。
+  - `auth_recovery_code` 表（`user_id / code_hash / used_at`）：恢复码**哈希**存（复用 Argon2 hasher），一次性。
+- **启用流程（opt-in）**：
+  1. `POST /api/auth/totp/setup`（已登录）→ 生成 pending secret + `otpauth://` URI + 一组恢复码（**仅此一次明文返回**），尚未启用。
+  2. `POST /api/auth/totp/enable`（带一个当前 6 位码确认）→ `totp_enabled=true`，持久化恢复码哈希。
+  3. `POST /api/auth/totp/disable`（带密码或当前码）→ 关闭、清 secret/恢复码。
+- **登录二因子（单端点、无独立 challenge token，保持无状态）**：
+  - `POST /api/auth/login` body 增可选 `totp_code`。
+  - 密码通过且 `totp_enabled`：无 `totp_code` → 返回 401 + `{totp_required: true}`（**不发 session**）；有 `totp_code` → 校验 TOTP **或**恢复码（命中恢复码则消费它）→ 通过才发 session。
+  - 未启用 TOTP：维持现状单步。
+  - 退避（§3.1）对两步都生效。
+- **issuer 标签**：`AUTH_TOTP_ISSUER`（默认 `app_name`），显示在 Authenticator app 里。
+
+### 3.4 前端
+
+- **登录页两步**：`LoginPage` 在收到 `401 + totp_required` 时切到第二屏（6 位码输入，也接受恢复码），再次 `POST /api/auth/login` 带 `totp_code`。被退避（429）显示"稍后再试"（用 `Retry-After`）。
+- **设置页 TOTP 区**：未启用→「启用」走 setup（展示二维码 + 恢复码一次性、要求输入码确认）；已启用→「停用」。恢复码只在生成时展示一次，提示妥善保存。
+
+## 4. API 契约（M4 要落地的端点）
+
+> 全部 `/api`、写端点 session + CSRF 保护、JSON 进出；schema 经 `export_openapi.py` 固化。
+
+| 分组 | 端点 | 用途 |
+| --- | --- | --- |
+| 登录 | `POST /api/auth/login` | 加退避（429+Retry-After）；body 增可选 `totp_code`；启用 TOTP 且缺码→401 `{totp_required:true}` |
+| TOTP | `POST /api/auth/totp/setup` | 生成 pending secret + otpauth URI + 恢复码（一次性）|
+| TOTP | `POST /api/auth/totp/enable` | 带当前码确认启用 |
+| TOTP | `POST /api/auth/totp/disable` | 关闭 TOTP |
+| TOTP | `GET /api/auth/totp` | 返回当前 TOTP 状态（enabled 与否）|
+
+> CLI 不是 HTTP 端点。throttle 开关与 issuer 走现有 `GET/PUT /api/config`（仅加 CONFIG_FIELDS）。
+
+## 5. 已锁定决策（讨论后拍板）
+
+1. **M4 独立里程碑、排在 M5 之前**。
+2. **范围**：防爆破 + 指数退避 + CLI 重置（密码/解锁/关 TOTP）+ TOTP（**可选配，非强制**）。
+3. **退避双键（IP + username）、延迟非永久锁定、成功清零、CLI 兜底**；反代后需开 `AUTH_TRUST_FORWARDED_FOR`。
+4. **CLI 逃生通道不依赖任何已存恢复凭据**；只动 auth 行，不碰用户数据。
+5. **TOTP 单端点二因子**（login 加可选 `totp_code`，无独立 challenge token）；恢复码哈希存、一次性；secret 明文存（与现有一致）。
+6. **二维码前端渲染**（`qrcode.react`），后端只给 `otpauth://` URI + secret；Python 仅加 `pyotp`。
+7. **CLI 入口 = `python -m scripts.admin_cli`**（无 console_scripts）。
+
+> 项目定位：个人自用、单 admin——可按单用户简化，不为多租户/找回邮件等过度设计。
+
+## 6. 任务依赖图
+
+```
+Phase A（防爆破，紧急，自成可发版增量）
+  M4-T01 [schema] auth_login_throttle 表 + 模型
+   └─► M4-T02 退避 service + 接入 login（429/Retry-After/成功清零）
+   └─► M4-T03 CLI 骨架 + reset-password + unlock
+
+Phase B（TOTP，可选配）
+  M4-T04 [schema] AuthUser TOTP 字段 + auth_recovery_code 表
+   ├─► M4-T05 TOTP service + setup/enable/disable/status API
+   ├─► M4-T06 登录二因子（login 加 totp_code；依赖 T02 已改过 login）
+   └─► M4-T07 CLI disable-totp / reissue-totp
+        M4-T08 前端：两步登录 + 设置页 TOTP（依赖 T05+T06；引入 qrcode.react）
+
+收尾
+  M4-T09 文档 + OpenAPI + roadmap（依赖全部）
+```
+
+`T01` 可先开。Phase A（T01–T03）跑完即可发一版只含防爆破 + CLI 的安全增量。
+
+---
+
+## 7. 原子任务（任务卡）
+
+> 后端沿用校验闸门（`pytest`/`ruff`/改路由或 schema 则 `export_openapi` 重导出入库）。前端闸门见 §8。新增依赖（`pyotp`、`qrcode.react`）须同步 `requirements.in/.txt` 与 `frontend/package.json` 重新锁定。
+
+### M4-T01 — `auth_login_throttle` 表 + 模型 `[schema]`
+- **Status**: `done` · **Depends**: none
+- **Context**: 存按 IP / username 的失败退避状态。仅建 schema。
+- **Files**: `create app/models/auth_throttle.py`（或并入 `app/models/auth.py`）；`create alembic_app/versions/<date>_NN_auth_login_throttle.py`；`modify alembic_app/env.py`、`scripts/app_db_adopt.py`（baseline 常量）；`create tests/test_auth_throttle_model.py`
+- **Steps**: 模型 `LoginThrottle`（`id / key str / scope str('ip'|'user') / failures int / first_failed_at / last_failed_at / next_allowed_at`，`(scope,key)` unique 索引）；新 revision 建表 + 索引；更新 baseline 常量。
+- **Out of scope / 不要碰**: 不写退避逻辑（T02）；不动登录端点。
+- **Acceptance criteria**:
+  - [ ] 临时库 upgrade 到 head 含该表与唯一索引；`downgrade -1` 干净。
+  - [ ] `APP_BASELINE_REVISION` 更新；`env.py` 已 import。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: `(scope,key)` 唯一；链上单 head；env.py 注册模型。
+
+### M4-T02 — 退避 service + 接入登录
+- **Status**: `done` · **Depends**: M4-T01
+- **Context**: 指数退避核心 + 接 `POST /api/auth/login`。
+- **Files**: `create app/services/login_throttle.py`；`modify app/api/routes/api/session.py`、`app/services/config_page.py`(+`CONFIG_FIELDS` `AUTH_LOGIN_THROTTLE_ENABLED`)、`app/config.py`(+`auth_login_throttle_enabled`、`auth_trust_forwarded_for`)；`modify tests/test_api_session.py`、`create tests/test_login_throttle.py`
+- **Steps**:
+  1. `check_and_get_wait(session, *, ip, username) -> int`（秒；>0 表示仍在窗口）；`register_failure(...)`（更新双键 failures/next_allowed_at，按 §3.1 公式）；`clear(session, *, ip, username)`（成功清零）。
+  2. 登录端点：取 client IP（按 `auth_trust_forwarded_for` 决定是否信 XFF 最左）；**先**查退避，>0 → 429 + `Retry-After`，不验密码；验密码失败 → `register_failure` 后 401；成功 → `clear` 再发 session。
+  3. 开关关闭时整段 no-op。
+- **Out of scope / 不要碰**: 不做 TOTP（Phase B）；不改 logout/password 端点。
+- **Acceptance criteria**:
+  - [ ] 单测：连续失败后 `wait` 按指数增长且封顶；窗口内请求 429 带 `Retry-After` 且不验密码。
+  - [ ] 单测：成功登录清零；下次无延迟。
+  - [ ] 401 仍为通用文案（不泄露用户是否存在）；现有登录测试仍绿。
+  - [ ] 开关 false 时无节流。
+  - [ ] 校验闸门全绿（OpenAPI 若变重导出）。
+- **Reviewer checklist**: 退避在验密码**之前**生效；双键较大值；XFF 仅在配置开启时信任；无把密码写进日志。
+
+### M4-T03 — CLI 骨架 + reset-password + unlock
+- **Status**: `done` · **Depends**: M4-T01
+- **Context**: 逃生通道第一批命令。
+- **Files**: `create scripts/admin_cli.py`；`create tests/test_admin_cli.py`
+- **Steps**: argparse 子命令；`reset-password <username> [--password|prompt(getpass)]` 用 Argon2 hasher 重置 `password_hash`；`unlock [--all|--ip|--username]` 删 `auth_login_throttle` 行；`list-admin`；复用 `get_session_local()` + 模型；无网络。
+- **Out of scope / 不要碰**: 不动 HTTP 端点；不碰用户数据表；TOTP 命令在 T07。
+- **Acceptance criteria**:
+  - [ ] 单测：`reset-password` 后新密码可 `verify_password` 通过、旧密码失败。
+  - [ ] 单测：`unlock` 清掉指定/全部退避行。
+  - [ ] 不存在的 user 友好报错、非零退出。
+  - [ ] `grep` 确认 CLI 不含对用户数据表的删除/drop。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 密码可交互输入且不回显；只动 auth 行；幂等可重跑。
+
+### M4-T04 — AuthUser TOTP 字段 + `auth_recovery_code` 表 `[schema]`
+- **Status**: `done` · **Depends**: none（与 Phase A 并行的 schema，但 T06 依赖 T02）
+- **Files**: `modify app/models/auth.py`（`AuthUser.totp_secret`/`totp_enabled`）；`create` 模型 `RecoveryCode`；`create alembic_app/versions/<date>_NN_totp.py`；`modify alembic_app/env.py`、`scripts/app_db_adopt.py`；`create tests/test_totp_models.py`
+- **Steps**: `totp_secret` nullable、`totp_enabled` bool default false；`auth_recovery_code(user_id FK, code_hash, used_at nullable)`；revision 建列 + 表；更新 baseline。
+- **Out of scope / 不要碰**: 不写 TOTP 逻辑（T05）。
+- **Acceptance criteria**:
+  - [ ] upgrade/downgrade 干净；默认 `totp_enabled=false`、`totp_secret=null`。
+  - [ ] baseline 常量更新；env.py import。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 现有用户迁移后默认未启用 TOTP（不破坏现有登录）。
+
+### M4-T05 — TOTP service + setup/enable/disable/status API
+- **Status**: `done` · **Depends**: M4-T04
+- **Files**: `create app/services/totp.py`、`app/schemas/totp.py`；`modify app/api/routes/api/session.py`（或新 `auth_totp.py` 路由）、`app/config.py`(+`auth_totp_issuer`)；`modify requirements.in/.txt`(+`pyotp`)；`create tests/test_api_totp.py`
+- **Steps**: pyotp 生成 secret + `otpauth://` URI（issuer=`auth_totp_issuer`）；恢复码生成（N=10、`xxxx-xxxx`，Argon2 哈希存、明文仅 setup 返回一次）；`setup`（pending，不启用）/`enable`（带当前码确认）/`disable`（带密码或当前码）/`GET status`；全部 session+CSRF。
+- **Out of scope / 不要碰**: 不改 login 校验（T06）。
+- **Acceptance criteria**:
+  - [ ] `setup` 返回 secret+URI+恢复码（一次性）；未确认前 `totp_enabled` 仍 false。
+  - [ ] `enable` 用错码失败、对码成功；恢复码以哈希持久化。
+  - [ ] `disable` 关闭并清 secret/恢复码。
+  - [ ] schema 经 OpenAPI 固化；secret/恢复码不回显于 `GET status`。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 恢复码只存哈希、明文仅一次；secret 不进 OpenAPI 示例/日志；`requirements.txt` 锁定 `pyotp`。
+
+### M4-T06 — 登录二因子（login 加 `totp_code`）
+- **Status**: `done` · **Depends**: M4-T05, M4-T02
+- **Files**: `modify app/api/routes/api/session.py`、`app/schemas/session.py`（`LoginRequest.totp_code` 可选）、`app/services/totp.py`（校验 + 消费恢复码）；`modify tests/test_api_session.py`、`tests/test_api_totp.py`
+- **Steps**: 密码通过后：若 `totp_enabled` 且无 `totp_code` → 401 `{totp_required:true}`（不发 session、退避照算）；有 `totp_code` → 校验 TOTP 或恢复码（命中恢复码置 `used_at`）→ 通过发 session；未启用 → 现状。
+- **Out of scope / 不要碰**: 不改 setup/enable（T05）；不动退避公式（T02）。
+- **Acceptance criteria**:
+  - [ ] 未启用 TOTP 的用户登录与现状完全一致。
+  - [ ] 启用后：缺码→401 totp_required；错码→401；对码→发 session；恢复码可用且一次性。
+  - [ ] 退避对二步同样生效。
+  - [ ] OpenAPI 重导出入库；校验闸门全绿。
+- **Reviewer checklist**: `totp_required` 时确未发 cookie；恢复码消费后不可复用；通用错误不泄露细节。
+
+### M4-T07 — CLI disable-totp / reissue-totp
+- **Status**: `done` · **Depends**: M4-T04（逻辑上配合 T03 的 CLI 骨架）
+- **Files**: `modify scripts/admin_cli.py`；`modify tests/test_admin_cli.py`
+- **Steps**: `disable-totp <username>`：`totp_enabled=false` + 清 secret + 删恢复码（**不需任何恢复码即可执行**）；`reissue-totp <username>`：生成新 secret（可选打印新 URI）。
+- **Out of scope / 不要碰**: 不碰用户数据表。
+- **Acceptance criteria**:
+  - [ ] 单测：启用 TOTP 的用户经 `disable-totp` 后可纯密码登录（结合 T06 行为）。
+  - [ ] 不依赖任何恢复码即可关停。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 逃生不依赖已存凭据；只动 auth 行。
+
+### M4-T08 — 前端：两步登录 + 设置页 TOTP
+- **Status**: `done` · **Depends**: M4-T05, M4-T06
+- **Files**: `modify frontend/src/pages/LoginPage.tsx`；`create frontend/src/pages/.../TotpSettings.tsx`（或并入 ConfigPage）、`frontend/src/auth/totp.ts`；`modify frontend/package.json`(+`qrcode.react`，lock 同步)；`create` 对应测试
+- **Steps**: 登录页：401+`totp_required`→第二屏 6 位码（也接受恢复码）；429→"稍后再试"（读 `Retry-After`）。设置页：未启用→启用流程（二维码由 `otpauth` URI 渲染 + 恢复码一次性展示 + 输码确认）；已启用→停用。
+- **Out of scope / 不要碰**: 不改后端；不碰防爆破逻辑。
+- **Acceptance criteria**:
+  - [ ] 未启用 TOTP 的登录体验不变；启用后两步可走通；恢复码可登录。
+  - [ ] 二维码可被 Authenticator 扫描；恢复码仅展示一次。
+  - [ ] 429 有"稍后再试"提示。
+  - [ ] 前端闸门全绿。
+- **Reviewer checklist**: 全走类型化 client；secret/恢复码不落 localStorage/日志；空/错/加载态有处理。
+
+### M4-T09 — 文档 + OpenAPI + roadmap 收尾
+- **Status**: `done` · **Depends**: 全部
+- **Files**: `modify README.md`、`docs/auth.md`（防爆破 + CLI + TOTP 说明、CLI 用法）、`docs/architecture-overview.md`；`modify docs/roadmap.md`（把"TOTP 二次验证"与新"登录防爆破"从「下一阶段」毕业、加 M4 行、注明 M4 先于 M5）；`modify docs/design/README.md`（已含 m4）；`run python scripts/export_openapi.py` 提交 `openapi/`
+- **Acceptance criteria**:
+  - [ ] 文档含 CLI 逃生用法与 TOTP 启停说明；`git diff --exit-code openapi/` 无差异。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: roadmap 反映 M4 已落地且先于 M5；无残留旧描述。
+
+---
+
+## 8. 前端校验闸门（前端任务每次结束都要全绿）
+
+在 `frontend/` 下：`npm ci && npm run lint && npm run typecheck && npm run test && npm run build`。新增依赖 `qrcode.react` 须提交 `package.json` + `package-lock.json`。后端同任务改路由/schema 仍需根目录 `export_openapi.py` 并提交 `openapi/`。
+
+## 9. 构建上下文 / 依赖完整性
+
+- 新增 Python 依赖 `pyotp`、前端 `qrcode.react`：同步重新锁定 `requirements.txt` / `package-lock.json`，否则镜像缺包。
+- 新文件均在既有 `app/`、`scripts/`、`frontend/` 的 COPY 范围内；`scripts/admin_cli.py` 须在镜像里可 `python -m scripts.admin_cli` 调用（确认 `scripts/` 已进镜像）。
+- `tests/test_deployment.py::test_dockerfile_copy_sources_exist` 仍应通过。
+
+## 10. 人工验收 walkthrough（实现完成后）
+
+> 重点：连续输错 → 系统自动退避锁住 → CLI 解锁后恢复登录。可用 `docker compose` 起服务，CLI 在容器内或容器外跑均可。
+
+**准备**：起服务（任选其一）
+- Docker：`docker compose up -d`（应用容器名见 `docker-compose.yml`，下文记为 `<app>`）。
+- 或本地：`source .venv/bin/activate && uvicorn app.main:app --port 8000`。
+
+**1) 触发退避锁定** —— 用**错误密码**连续登录同一账号：
+```bash
+for i in $(seq 1 8); do \
+  code=$(curl -s -o /dev/null -w "%{http_code}" -X POST http://localhost:8000/api/auth/login \
+    -H 'Content-Type: application/json' -d '{"username":"admin","password":"wrong"}'); \
+  echo "尝试 $i -> HTTP $code"; done
+```
+- 预期：前几次 `401`，超过免费次数后变 `429`（被锁/退避）。单独跑一次带 `-i` 可看到 `Retry-After` 头逐次增大（指数退避）。
+- 在退避窗口内，**即使输正确密码**也应被 `429` 挡住（验证锁定确实生效）。
+
+**2) CLI 解锁**
+- 容器内：`docker compose exec <app> python -m scripts.admin_cli unlock --all`
+- 或容器外：`python -m scripts.admin_cli unlock --all`
+- 预期：打印清除的退避条目数。
+
+**3) 验证恢复** —— 立即用**正确密码**登录：
+```bash
+curl -i -X POST http://localhost:8000/api/auth/login \
+  -H 'Content-Type: application/json' -d '{"username":"admin","password":"<正确密码>"}'
+```
+- 预期：`200` 且 `Set-Cookie` 下发 session → 解锁成功。
+
+**4)（可选）其它逃生命令**
+- 重置密码：`python -m scripts.admin_cli reset-password admin`（交互输入新密码、不回显）。
+- 关停 TOTP（若已启用）：`python -m scripts.admin_cli disable-totp admin`，随后纯密码即可登录。
+
+## 11. 里程碑完成定义（DoD）
+
+- 登录失败按指数退避（429 + Retry-After），成功清零；可经 `AUTH_LOGIN_THROTTLE_ENABLED` 开关。
+- `python -m scripts.admin_cli` 能在**无任何 Web 访问、无恢复码**的情况下重置密码 / 解锁 / 关停 TOTP。
+- TOTP 可由 admin 自选启用：启用后两步登录、恢复码可用且一次性；不启用维持纯密码。
+- 后端 `pytest`/`ruff`/`export_openapi` + 前端 `lint/typecheck/test/build` 全绿且 `openapi/` 入库。
+- README/auth/architecture/roadmap 反映 M4 现实与"先于 M5"的排期。
@@ -0,0 +1,533 @@
+# M5 — IoT 集成与能耗采集（Modbus 设备采集 + MQTT/HA Discovery + 前端侧边栏）
+
+> 阅读前提：先读 [`README.md`](./README.md)（协作模型、任务卡格式、校验闸门、数据安全红线）。本里程碑建立在 M1 单库 + M2 React SPA 之上。
+> 配套参考：电表协议见 [`../references/SDM120-Modbus-Protocol.md`](../references/SDM120-Modbus-Protocol.md)。
+
+## 1. 目标
+
+给后端接入家庭 IoT 生态，并新增一条通用的 Modbus 设备采集链路（首个落地的领域是能耗）：
+
+1. **Modbus 设备采集（通用管道）**：通过 Modbus-TCP 网关周期读取挂在网关后面的 Modbus slave 设备（首个 profile 为 SDM120 单相电表），按设备的 **YAML profile** 解码为工程量，存入单库的**通用读数表**。后台静默轮询，支持多设备、多 profile。
+2. **MQTT + Home Assistant Discovery**：后端作为 MQTT 发布方，按"**可勾选暴露**"的方式把数据以 HA Discovery 自动注册成 device/entity（不止 sensor）。
+3. **前端侧边栏 + Energy 视图**：把现有顶栏改成侧边导航，承载首个领域视图 **Energy**（设备管理 + 最新读数 + 走势图）。
+
+> **命名分层（本里程碑的核心决策）**：**存储 / 采集 / API 是通用的 `modbus_*`**（不锁死在"电表"上，以后接别的 Modbus 设备无需改表）；**面向用户的呈现是领域特定的**——本里程碑只落第一个领域视图 **Energy**，消费通用 device 数据、用电表视角展示。
+
+> 三段有依赖关系，按 §6 的 `Depends` 顺序推进：A（侧边栏，独立）→ B（Modbus 采集后端 + Energy 前端）→ C（MQTT/Discovery，消费 B 的数据）。
+
+## 2. 现状（实现者可据此工作，不必通读全仓库）
+
+**单库数据层**（M1 完成态）
+- `app/db.py`：`class Base(DeclarativeBase)`，绑 `settings.app_database_url` 的 cached engine（WAL 已开），`get_engine` / `get_session_local` / `reset_db_caches` / `get_db_session`。
+- 模型都继承同一 `Base`：`app/models/{auth,config,public_ip,location,poo}.py`。
+- 单 Alembic 链 `alembic_app/`，head = `20260611_06_merge_location_poo_tables`（见 `alembic_app/versions/`）；`alembic_app/env.py` 逐个 import 所有模型。
+- 迁移命名惯例：`YYYYMMDD_NN_<desc>.py`，`revision` / `down_revision` 串链。
+- `scripts/app_db_adopt.py` 常量 `APP_BASELINE_REVISION` 指向当前 head；`scripts/run_migrations.py` 负责把 app 库升到 head。
+
+**配置系统（扁平 KV，自动渲染）**
+- `app/config.py`：`class Settings(BaseSettings)`，每个配置项一个带类型的字段 + 默认值。
+- `app/services/config_page.py`：`CONFIG_FIELDS: tuple[ConfigField, ...]` 是**注册表**（`section / env_name / setting_attr / label / secret / input_type`）；`build_config_sections`（读，secret 回空串）、`save_config_updates`（写，空 secret 保留旧值）、`build_runtime_settings`（DB override 合并进 Settings）、`_settings_payload`（把 Settings 摊平成 dict，新字段要在此补一行）。
+- `app/api/routes/api/config.py`：`GET/PUT /api/config`，session + CSRF 保护；非法值 422 且不写库。
+- 前端 `frontend/src/pages/ConfigPage.tsx`：**通用渲染**——按 section 分组、按 `input_type`/`secret` 渲染输入框。**新增标量配置项零前端改动**（追加 `CONFIG_FIELDS` + `Settings` 字段 + `_settings_payload` 一行即可）。
+- ⚠️ 扁平 KV **装不下"设备列表"和"逐实体勾选"**——这两者走专用表 + 专用 API + 自定义 UI（见 §3.2 / §3.4）。
+
+**后台调度（APScheduler）**
+- `app/main.py` lifespan：`BackgroundScheduler(timezone="UTC")`，`scheduler.add_job(_run_scheduled_public_ip_check, IntervalTrigger(hours=4), id=..., max_instances=1, coalesce=True)`，`scheduler.start()`；`yield` 后 `scheduler.shutdown(wait=False)`。
+- 周期任务惯例：一个**同步** wrapper 自己开/关 session：`session = get_session_local()(); try: service(session, ...) finally: session.close()`，service 内部不抛崩溃。
+
+**Home Assistant 现状（REST，不碰 MQTT）**
+- `app/integrations/homeassistant.py`：`HomeAssistantClient.publish_sensor()`（`POST /api/states/{entity}`）、`trigger_webhook()`。
+- 入站 webhook `app/api/routes/homeassistant.py`：`POST /homeassistant/publish`（envelope `target/action/content`）。
+- 新 MQTT Discovery 与此**并行、不冲突**，是第二条独立通道。
+
+**前端（M2）**
+- React + react-router v6 + Mantine + TanStack Query + `openapi-fetch` 生成的类型化 client（`frontend/src/api/client.ts` + `schema.d.ts`）。
+- `frontend/src/App.tsx`：`AppLayout`（当前是**顶栏**），包住所有受保护页；路由 `/`(HomePage 地图)、`/config`、`/records`；`/login`、`/change-password` 不带 layout。
+- 数据请求惯例：`useQuery`/`useMutation` + `apiClient.GET/POST/...`（见 `frontend/src/records/hooks.ts`）。
+- **无图表库**（只有 Leaflet 地图）；走势图需新引入 **Recharts**。
+
+## 3. 目标架构
+
+### 3.0 两层数据模型（本里程碑的地基决策）
+
+把"设备是什么、怎么读"与"读到了什么"彻底分成两层，**协议知识与部署信息分离**：
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│ 协议层（固定，随代码走）         部署层（可配置，落 DB）       │
+│ ── YAML profile ──────────       ── modbus_device 行 ──────   │
+│ • 读哪些寄存器（FC/地址/块）     • friendly_name（可改）       │
+│ • 每个量：key / 类型 / 解码      • host / port（网关）          │
+│ • 每个量：unit / device_class    • unit_id（=电表 Meter ID，   │
+│   / ha_component                   设备上可设，故落 DB）        │
+│ • 唯一真相源，喂给"读/存/HA注册" • profile 名（选哪个 YAML）    │
+│                                  • uuid / poll_interval / enabled│
+└─────────────────────────────────────────────────────────────┘
+        ▲ 多个 device 可共享同一 profile         │
+        └─────────────────────────────────────────┘
+                          │ 采集
+                          ▼
+            ── modbus_reading 行（通用遥测）──
+            device_id · recorded_at · payload(JSON blob)
+```
+
+- **profile = 仓库内只读 YAML**（如 `app/integrations/modbus/profiles/sdm120.yaml`），随镜像打包、纳入版本控制，**只描述固定协议知识**：读哪些寄存器、怎么解码、每个量的 `key`/`unit`/`device_class`/`ha_component`。**绝不**放 friendly_name / unit_id 这类每设备各异的可配置项。
+- **可配置项落 `modbus_device` 行**，由前端 UI 设置：friendly_name、host、port、**unit_id（Modbus 从机地址，设备面板上可改）**、选用的 profile 名、poll_interval、enabled。
+- **多设备共享一个 profile**：例如两块 SDM120 都 `profile="sdm120"`，一块 friendly_name="SDM120 空调"、unit_id=1，另一块 friendly_name="SDM120 服务器"、unit_id=2——共用同一份解码规则，部署参数各自独立。
+- **读数存通用 JSON `payload`**，不再用固定列。profile 是解释器：知道 payload 里有哪些 key、各自单位与 device_class。
+  - 聚合不必搬到后端硬算：**SQLite 用 `json_extract` 在 SQL 端做 `AVG`/`MAX`/`GROUP BY`**（走势图都是带时间窗的查询，被 `(device_id, recorded_at)` 索引圈住，只扫窗内行）。
+  - 真有某个量需要高频聚合 → 后续给该量加 **generated column + 表达式索引**（非破坏性，要哪个补哪个），无需一开始把表锁成固定列。
+
+### 3.1 Modbus 采集
+
+- **传输：仅 Modbus-TCP**（用户的 Waveshare RTU↔TCP 网关，RJ45 以太网；服务器无串口）。用 **pymodbus** 的 `ModbusTcpClient`，由它处理封帧 / CRC / 超时重试 / float 解码。
+  - 角色厘清：**我们的后端 = Modbus client/master**；**网关 = TCP server**（在 "Modbus TCP" 模式下终结 TCP 再转 RTU）；**电表 = 网关后面的 RTU slave**，由 `unit_id` 寻址。`modbus_device` 一行同时装下网关地址（host:port）与 slave 地址（unit_id）。
+  - 网关若开"Modbus TCP"协议转换 → pymodbus 默认 framer 直连。
+  - 网关若是透传（RTU-over-TCP，裸 RTU 帧含 CRC）→ pymodbus 用 RTU framer over TCP。
+  - **二者实现时对一次即可确定**（连上读 Voltage 寄存器验证），不影响表结构与上层。
+- **协议知识在 YAML profile，部署信息在 DB**（见 §3.0）：
+  - `app/integrations/modbus/driver.py`：薄封装 pymodbus 的连接 + 块读 + 大端 float32 解码（word/byte 都大端，高寄存器在前）。
+  - `app/integrations/modbus/profiles.py`：YAML profile 的**加载 + 校验 + 解码 + 实体枚举**——纯"数据 + 函数"，**不做 OOP 抽象基类/继承**。`load_profile(name) -> ModbusProfile`（pydantic 模型，启动期校验）、`decode(profile, registers) -> dict[key -> value]`、`enumerate_entities(device, profile) -> list[ExposableEntity]`（供 §3.3）。
+  - `app/integrations/modbus/profiles/*.yaml`：每个设备型号一个 YAML。首个 = `sdm120.yaml`（寄存器地址见参考文档 §4）。
+  - profile 输出统一的 `dict[key -> value]`，由 service 整个塞进 `modbus_reading.payload`（JSON）；profile 没列出的量根本不读。
+- **只读**：不写电表配置寄存器（改 Meter ID/波特率有通信中断风险）。
+- **轮询**：每个设备一个 `poll_interval_s`（默认 5s），APScheduler 一个 job 扫所有 `enabled` 设备，逐设备块读→解码→落库。9600 总线上多设备串行，5s 余量充足。
+  - 全局开关 `MODBUS_POLLING_ENABLED`（CONFIG_FIELDS）可一键停采。
+  - 采集成功/失败写入设备的 `last_poll_at` / `last_poll_ok`（供 §3.3 的 online binary_sensor）。
+  - **两级周期 / 降采样 / 保留是后续杠杆**（见 §10），本里程碑用单周期读全。
+
+**`sdm120.yaml` 示例（只含固定协议知识）**
+
+```yaml
+name: sdm120
+description: Eastron SDM120 single-phase energy meter
+function_code: 4          # input registers (FC04)
+word_order: big           # 高寄存器在前
+byte_order: big
+blocks:                   # 块读，减少 Modbus 事务
+  - { start: 0x0000, count: 0x0060 }   # 30001..30095 连续段
+  - { start: 0x0156, count: 0x0004 }   # total active/reactive energy
+metrics:
+  - { key: voltage,            address: 0x0000, type: float32, unit: V,   device_class: voltage,    ha_component: sensor }
+  - { key: current,            address: 0x0006, type: float32, unit: A,   device_class: current,    ha_component: sensor }
+  - { key: active_power,       address: 0x000C, type: float32, unit: W,   device_class: power,      ha_component: sensor }
+  - { key: power_factor,       address: 0x001E, type: float32, unit: "",  device_class: power_factor, ha_component: sensor }
+  - { key: frequency,          address: 0x0046, type: float32, unit: Hz,  device_class: frequency,  ha_component: sensor }
+  - { key: import_energy,      address: 0x0048, type: float32, unit: kWh, device_class: energy, state_class: total_increasing, ha_component: sensor }
+  - { key: export_energy,      address: 0x004A, type: float32, unit: kWh, device_class: energy, state_class: total_increasing, ha_component: sensor }
+  - { key: total_energy,       address: 0x0156, type: float32, unit: kWh, device_class: energy, state_class: total_increasing, ha_component: sensor }
+# 冷门量（demands / maxima / 无功电能…）可后续按需补进 metrics；未列出的就不读。
+```
+
+> 注意 YAML 里**没有** unit_id / friendly_name——那些是 `modbus_device` 行各自带的。
+
+### 3.2 数据模型（新增两张通用表，单库 app 链）
+
+**`modbus_device`**（设备定义 = 部署/可配置项，CRUD 管理）
+
+| 列 | 类型 | 说明 |
+| --- | --- | --- |
+| id | int PK | 内部代理主键（FK join 用）|
+| uuid | str unique | uuid4 生成的**稳定内部身份**；也作 API 路径键与 HA `unique_id` 的锚 |
+| friendly_name | str | 显示名（可改；改名重发 discovery，HA 显示名跟着变）|
+| transport | str | 现仅 `'tcp'` |
+| host | str | 网关 IP |
+| port | int | 网关端口（默认 502）|
+| unit_id | int | Modbus 从机地址 = 电表 Meter ID（设备面板可改，默认 1）|
+| profile | str | 用哪个 YAML profile（首个 `'sdm120'`）|
+| poll_interval_s | int | 采样周期（默认 5）|
+| enabled | bool | 是否轮询 |
+| last_poll_at | datetime null | 最近一次轮询时刻（online 判定）|
+| last_poll_ok | bool null | 最近一次轮询成败（online 判定）|
+| created_at / updated_at | datetime | |
+
+**`modbus_reading`**（通用遥测表，一行 = 一个设备的一次采样）
+
+| 列 | 类型 | 说明 |
+| --- | --- | --- |
+| id | int PK | |
+| device_id | int FK→modbus_device.id | **ON DELETE RESTRICT**（见 §5 删除语义）|
+| recorded_at | datetime (UTC) | 采样时刻，**真实列、带索引**（所有查询按它走时间窗）|
+| payload | JSON | profile 解码出的全部工程量 `{key: value}`；无固定列 |
+
+- 索引：`(device_id, recorded_at)`。
+- **SDM120 单相 payload 示例**：`{"voltage": 230.2, "current": 1.3, "active_power": 295.0, "power_factor": 0.98, "frequency": 50.0, "import_energy": 123.4, "export_energy": 0.0, "total_energy": 123.4}`——key 由 `sdm120.yaml` 的 `metrics[].key` 决定。
+- **接入新设备型号无需改表**：换 profile，payload 里的 key 集合随之变；表结构不动。
+- **三相电表**以后用三相 profile，payload 里多几个相位 key（如 `voltage_l1/l2/l3`），仍是同一张表。
+
+### 3.3 MQTT + HA Discovery（通用 expose 框架，元数据由 profile 派生）
+
+HA MQTT Discovery 模型 = **device → entities**：往 `<prefix>/<component>/<node>/<object>/config` 发 retained 消息定义一个 entity；config 内 `device.identifiers` 相同的 entity 归到同一个 HA device 卡片下；之后往 `state_topic` 推值。
+
+- **可暴露实体目录由 provider 动态产出**：
+  - `app/integrations/expose.py`：定义 `ExposableEntity`（`key`（稳定）、`component`（sensor/binary_sensor/switch…）、`device`（归属，决定 HA device 分组）、`device_class`、`unit`、取值来源）+ 一个 provider 注册表。
+  - **Modbus/energy provider**：每个 `enabled` 设备 = 一个 HA **device**（`identifiers` 用设备 `uuid`），其各工程量 = 一组 sensor entity——**`device_class`/`unit`/`component` 直接取自该设备 profile 的 `metrics[]`**（不再单独维护一份映射），外加一个 `binary_sensor`「online」（取 `last_poll_ok`）——这就是"**不止 sensor**"的体现。
+  - 其它 provider（如 public-ip、poo）可后续挂入，本里程碑只接 Modbus/energy provider。
+- **HA 实体身份锚定（Z2M 模型）**：discovery config 的 **`unique_id` 用设备 `uuid` + 量的 `key` 派生**（稳定，不随改名变）；可见的 **`name` 用 friendly_name**。改 friendly_name → 重发 discovery → HA 显示名跟着变、但 `unique_id` 不变故历史不丢。topic 的 object_id 也用 uuid 派生（稳定、丑无所谓）。
+- **`exposed_entities` 表**：只存"逐 key 的开关"（`key` unique + `enabled` + `updated_at`）。目录本身由 provider 计算，表只记被勾选的状态（默认未勾 = 不暴露）。
+- **MQTT 客户端**：`app/integrations/mqtt.py` 用 **paho-mqtt**，`loop_start()` 后台线程；在 lifespan 起/停；支持配置变更后**重连 + 重发 discovery**。
+- **发布时机**：
+  - discovery config（retained）：连接成功时、目录/勾选变更时全量发；取消勾选时发空 payload 清除该 entity。
+  - state：采集在每次轮询后推最新值；另有一个周期 job 兜底重发所有 enabled 实体的 state + availability（在线）topic。
+- **配置**（走现有扁平 CONFIG_FIELDS）：`MQTT_ENABLED`、`MQTT_BROKER_HOST/PORT/USERNAME/PASSWORD(secret)`、`MQTT_TLS_ENABLED`、`HA_DISCOVERY_ENABLED`、`HA_DISCOVERY_PREFIX`（默认 `homeassistant`）。
+
+### 3.4 前端
+
+- **侧边栏**：把 `AppLayout` 从顶栏重构为侧边导航（Mantine `AppShell` 或 flex sidebar），导航项：Home / Records / Energy / Config + 主题切换 + 注销；当前路由高亮；移动端可折叠。仅改 `App.tsx`（+ 可抽 `AppSidebar`/`NavItem` 组件），各页面主体不动。
+- **Energy 视图**（新页 `/energy`，首个领域视图，消费通用 `/api/modbus` 数据）：
+  - 设备管理：列表 + 新建/编辑/删除（删除有二次确认；后端对有读数的设备拒删，引导改用"禁用"）。新建/编辑表单里设 friendly_name、host、port、unit_id、profile（下拉选 `sdm120` 等）、poll_interval、enabled。
+  - 最新读数卡片（每设备当前各工程量；字段标签/单位取自 profile 的 metrics 元数据，见 `/metrics` 端点）。
+  - 走势图：用 **Recharts** 画时间序列（电压/电流/功率/电能），时间范围选择，取数走 readings API（窗口 + 上限），从 `payload` 里按 key 取序列。
+- **Expose 设置**：设置页内一块「Home Assistant Expose」——列出可暴露实体目录、逐项勾选、显示 MQTT/Discovery 连接状态、一个"重新发布 discovery"按钮。
+
+## 4. API 契约（M5 要落地的端点）
+
+> 全部 `/api` 前缀、session + CSRF（写）保护、JSON 进出。schema 经 `export_openapi.py` 固化入库。路径键用设备 `uuid`（稳定、非自增）。
+
+| 分组 | 端点 | 用途 |
+| --- | --- | --- |
+| Modbus | `GET /api/modbus/devices` | 列出设备 |
+| Modbus | `POST /api/modbus/devices` | 新建设备 |
+| Modbus | `GET /api/modbus/devices/{uuid}` | 单个设备 |
+| Modbus | `PATCH /api/modbus/devices/{uuid}` | 修改设备（含 enable/disable）|
+| Modbus | `DELETE /api/modbus/devices/{uuid}` | 删除设备；**有读数时 409**，引导改 disable |
+| Modbus | `GET /api/modbus/devices/{uuid}/metrics` | 该设备 profile 的量目录（key/label/unit/device_class），供前端渲染卡片与图表标签 |
+| Modbus | `GET /api/modbus/devices/{uuid}/latest` | 该设备最新一条读数（payload）|
+| Modbus | `GET /api/modbus/devices/{uuid}/readings` | 时间范围读数（`start/end/limit`，limit 有上限），返回 `recorded_at + payload`，供走势图 |
+| Modbus | `POST /api/modbus/devices/{uuid}/test` | 即时试读一次（验证网关连通/地址），返回解码 payload，不落库 |
+| Modbus | `GET /api/modbus/profiles` | 列出可用 profile 名 + 描述（前端建设备时的下拉选项）|
+| Expose | `GET /api/expose` | 返回可暴露实体目录 + 勾选状态 + MQTT/Discovery 状态 |
+| Expose | `PUT /api/expose` | 设置逐 key 勾选（map key→bool）|
+| Expose | `POST /api/expose/republish` | 手动重发 discovery |
+| 配置 | `POST /api/config/mqtt/test` | 试连 broker **并发布一条测试消息**（MQTT Explorer 可见），仿 SMTP 测试三态 |
+
+> MQTT broker / discovery 的**标量配置**复用现有 `GET/PUT /api/config`（只新增 CONFIG_FIELDS，不新增端点）。
+
+## 5. 已锁定决策（讨论后拍板）
+
+1. **里程碑编排**：一个 M5 文档分三段，`Depends` 串顺序（A 侧边栏 → B Modbus/Energy → C MQTT）。
+2. **两层数据模型，协议与部署分离**：`modbus_device`（部署/可配置项：friendly_name、host、port、unit_id、profile 名、poll、enabled）+ `modbus_reading`（通用遥测：device_id、recorded_at、`payload` JSON）。取代原"宽表 + 固定列"。
+3. **读数 = JSON `payload`，无固定列**；聚合走 SQLite `json_extract`（DB 端做 AVG/MAX/GROUP BY），热点量后补 generated column + 表达式索引。两级周期/降采样为后续杠杆。
+4. **协议知识 = 仓库内只读 YAML profile**（声明式"数据 + 函数"，无 OOP 继承，pydantic 启动期校验）；YAML 携带寄存器 + 每个量的 key/unit/device_class/ha_component，是**唯一真相源**，同时驱动"读 / 存 / HA 注册"。多设备可共享一个 profile。首个 profile `sdm120`。
+5. **Modbus 仅 TCP**，pymodbus，framer 配网关模式，**只读**采集。设备是网关后面的 slave，`unit_id` 寻址（设备面板可改，故落 DB）。
+6. **命名分层（方案 C）**：存储/采集/API 一律通用 `modbus_*`、`/api/modbus/devices`；前端首个领域视图叫 **Energy**（消费通用 device 数据）。
+7. **UUID = 内部生成（uuid4）的稳定身份**：既做内部索引/ API 路径键，也做 HA discovery `unique_id` 的锚；friendly_name 可改，改名重发 discovery、HA 显示名跟着变（Z2M 模型，历史不丢）。
+8. **MQTT = 通用 expose 框架**：provider 动态产出可暴露实体目录，**实体元数据（device_class/unit/component）从 profile 派生**；`exposed_entities` 只存逐 key 开关；支持 sensor/binary_sensor/switch 等多 component；设备自动注册（每设备一 device、各量为 entity + 一个 online binary_sensor）。
+9. **MQTT 库 = paho-mqtt**，lifespan 长连接，配置变更后重连 + 重发 discovery。
+10. **MQTT broker/discovery 标量配置走现有扁平 CONFIG_FIELDS**（自动渲染）；设备清单与 expose 勾选走专用表 + 自定义 UI。
+11. **图表库 = Recharts**（封在自包含组件后，仿 M2 对 Leaflet 的隔离）。
+12. **删除设备安全**：FK `ON DELETE RESTRICT`，有读数拒删（避免一键删表丢历史）；"停用"用 `enabled=false`。
+13. **Config 页用 Accordion 分区**（进页见大类、逐类展开），**不在 config 页内再放第二个 side nav**——避免与主侧栏（T01）的"双抽屉"冲突；纯前端、独立任务 M5-T01B。
+14. **CLI 手工测试工具为"受控手工链路验证"而设**（设备接市电、非随时在线，不进自动化）：`scripts/modbus_cli` 提供 `read`（profile 解码）与 `probe`（手工指定请求内容、看原始回复）两个子命令，**一律只读**（仅 FC03/04），不暴露写寄存器。
+15. **MQTT/HA 发布链路的手工验证走 UI + 外部工具，不另做 CLI**：Config 页「发送测试消息」（`mqtt/test` 发一条到测试 topic）→ 在 **MQTT Explorer** 查看；Expose 勾选实体 + 开 `HA_DISCOVERY_ENABLED` + 「重新发布 discovery」（`/api/expose/republish`）→ 到 **Home Assistant** 查看。不通则迭代配置再重发。
+
+> 项目定位：个人自用、家庭特化、不开源——可按单用户场景简化，不过度抽象。
+
+## 6. 任务依赖图
+
+```
+Phase A（独立，可最先做，纯前端）
+  M5-T01  [structural] 侧边栏布局重构
+  M5-T01B Config 页分区折叠（Accordion）   ← 与 T01 互不依赖，可并行/先后任意
+
+Phase B（Modbus 采集 + Energy 前端）
+  M5-T02 [schema] modbus_device + modbus_reading 表 + 模型
+   ├─► M5-T03 Modbus 驱动 + YAML profile 框架（pymodbus + sdm120.yaml，纯模块）
+   │     └─► M5-T04 采集 service + APScheduler 轮询（接 lifespan，落 payload）
+   └─► M5-T05 Modbus JSON API（device CRUD + readings + metrics + test）
+            └─► M5-T06 前端：设备管理 UI（依赖 T01 侧栏 + T05 API）
+            └─► M5-T07 前端：读数展示 + Recharts 走势图（依赖 T05；引入 recharts）
+
+Phase C（MQTT / Discovery，依赖 B 的设备数据与 provider 接口）
+  M5-T08 MQTT/Discovery 配置项（CONFIG_FIELDS）
+  M5-T09 [schema] exposed_entities 表 + ExposableEntity/provider 框架（modbus provider 从 profile 派生）
+   ├─► M5-T10 MQTT 客户端（paho，lifespan 连接 + 重连 + config/mqtt/test）
+   │     └─► M5-T11 Discovery 发布 + state 发布（连 T04 轮询推 state）
+   └─► M5-T12 前端：Expose 勾选 UI + /api/expose API
+
+收尾
+  M5-T13 文档 + OpenAPI + roadmap 收尾（依赖全部）
+```
+
+`T01`、`T01B`、`T02`、`T08` 无前置可先开。
+
+---
+
+## 7. 原子任务（任务卡）
+
+> 后端任务沿用校验闸门（`pytest` / `ruff` / 改路由或 schema 则 `export_openapi` 重导出入库）。前端任务闸门见 §8。新增依赖（`pymodbus`、`PyYAML`、`paho-mqtt`、`recharts`）须在对应任务里同步 `requirements.in/.txt` 或 `frontend/package.json` 并重新锁定。
+
+### M5-T01 — 侧边栏布局重构 `[structural]`
+- **Status**: `done` · **Depends**: none
+- **Context**: 把 `AppLayout` 从顶栏改为侧边导航，给后续 Energy 等视图腾入口。纯前端，不碰各页主体。
+- **Files**: `modify frontend/src/App.tsx`；`create frontend/src/components/AppSidebar.tsx`、`frontend/src/components/NavItem.tsx`（可选）；`modify` 受影响的 `frontend/src/pages/*.test.tsx`（导航断言）
+- **Steps**:
+  1. 用 Mantine `AppShell`（或 flex sidebar）重构 `AppLayout`：左侧竖直导航（Home/Records/Config + 主题切换 + 注销），`<Outlet/>` 在右。
+  2. 当前路由高亮（`useLocation` 比对 `pathname`）；移动端可折叠（burger）。
+  3. 导航项图标沿用 `react-feather`；样式走 Mantine（暗色模式自动适配）。
+  4. 不在本任务加 Energy 项（页面还不存在，T06 加），保持导航无死链。
+- **Out of scope / 不要碰**: 不改各页面主体；不动鉴权（SessionProvider/ProtectedRoute）；不引入图表库。
+- **Acceptance criteria**:
+  - [ ] 受保护页都在侧边栏布局内；`/login`、`/change-password` 不带布局（与现状一致）。
+  - [ ] 当前路由在侧栏高亮；移动端宽度下可折叠/展开。
+  - [ ] 前端闸门全绿（`lint`/`typecheck`/`test`/`build`）。
+- **Reviewer checklist**: 布局只在 `App.tsx`/新组件内变动，未误改页面或鉴权；无死链导航项。
+
+### M5-T01B — Config 页分区折叠（Accordion）
+- **Status**: `done` · **Depends**: none
+- **Context**: config 内容会越来越多（M5 还要加 MQTT / HA Discovery / Modbus 配置 + Expose 面板）。把 ConfigPage 从一长串 section 改为 Mantine `Accordion`：进页只见各大类标题，逐类展开编辑。**纯前端、单列内容**——它不是"第二个 app 级侧栏"，与主侧栏（T01）无冲突，故 `Depends: none`、可独立先做。
+- **Files**: `modify frontend/src/pages/ConfigPage.tsx`；`modify frontend/src/pages/ConfigPage.test.tsx`（折叠/展开断言）
+- **Steps**:
+  1. 用 Mantine `Accordion` 包住现有"按 section 分组"的渲染：每个 config section = 一个 `Accordion.Item`（标题 = section 名，面板 = 该 section 的字段表单）。
+  2. 默认折叠（或首个展开）；**保留现有保存逻辑与 config API 不变**（M2 的整页/按 section 保存语义照旧，本任务不碰后端）。
+  3. 预留：将来 T12 的「Home Assistant Expose」自定义面板也作为一个 `Accordion.Item` 接入，保持一致。
+  4. 移动端单列堆叠即可，**不引入第二个侧栏/抽屉**。
+- **Out of scope / 不要碰**: 不改后端 config API/字段（`CONFIG_FIELDS` / `_settings_payload`）；不动主侧栏（T01）；不改保存语义；不在 config 页内放任何 app 级 side nav。
+- **Acceptance criteria**:
+  - [ ] ConfigPage 以 accordion 呈现，每大类可独立展开/折叠；字段渲染与保存行为与现状一致。
+  - [ ] 与主侧栏无视觉/交互冲突（单列内容；移动端不出现双抽屉）。
+  - [ ] 前端闸门全绿（`lint`/`typecheck`/`test`/`build`）。
+- **Reviewer checklist**: 仅改 ConfigPage（+其测试），未碰 config 后端或主 layout；保存逻辑无回归；页面内**无第二个 app 级 sidebar**（accordion 是内容、非 chrome）。
+
+### M5-T02 — `modbus_device` + `modbus_reading` 表与模型 `[schema]`
+- **Status**: `done` · **Depends**: none
+- **Context**: 单库 app 链新增两张**通用**表，建出 §3.2 结构（设备 = 部署层，读数 = JSON payload 通用遥测层）。本任务只建 schema + 模型，不写采集/接口。
+- **Files**: `create app/models/modbus.py`（`ModbusDevice`、`ModbusReading`，继承 `app.db.Base`）；`create alembic_app/versions/<date>_07_modbus_tables.py`；`modify alembic_app/env.py`（import 新模型）；`modify scripts/app_db_adopt.py`（`APP_BASELINE_REVISION` → 新 head）；`create tests/test_modbus_models.py`
+- **Steps**:
+  1. 模型按 §3.2 列定义（`Mapped[...]` 2.0 风格）：`ModbusDevice` 含 `uuid`(unique)、`friendly_name`、`transport`、`host`、`port`、`unit_id`、`profile`、`poll_interval_s`、`enabled`、`last_poll_at`/`last_poll_ok`(nullable)、时间戳；`uuid` 用 `default` 生成 uuid4 字符串。`ModbusReading` 含 `device_id` FK→`modbus_device.id`（**`ondelete="RESTRICT"`**）、`recorded_at`、`payload`（JSON 列，非 null）。
+  2. 新 revision：`down_revision` = 当前 head；`upgrade()` 用 `op.create_table` 建两表 + 索引 `(device_id, recorded_at)`；`downgrade()` 反向 drop。
+  3. 更新 `APP_BASELINE_REVISION`。
+- **Out of scope / 不要碰**: 不写 pymodbus/采集（T03/T04）；不加路由（T05）；不动其它模型。
+- **Acceptance criteria**:
+  - [ ] 全新临时 app 库 upgrade 到 head 后含 `modbus_device`、`modbus_reading` 及索引；`downgrade -1` 干净回滚。
+  - [ ] `Base.metadata.tables` 含两新表；FK 为 RESTRICT；`uuid` 唯一且自动生成。
+  - [ ] `APP_BASELINE_REVISION` == 新 head。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 列/约束与 §3.2 一致；`payload` 为 JSON 列；`recorded_at` 为真实索引列（非塞进 payload）；链上单 head；`env.py` 已 import 新模型（否则 autogenerate/建表漏表）。
+
+### M5-T03 — Modbus 驱动 + YAML profile 框架（`sdm120`）
+- **Status**: `done` · **Depends**: M5-T02
+- **Context**: 薄封装 pymodbus 的连接/块读/大端 float 解码，加 YAML profile 加载/校验/解码框架与 SDM120 profile。纯模块，mock client 单测。
+- **Files**: `create app/integrations/modbus/__init__.py`、`app/integrations/modbus/driver.py`、`app/integrations/modbus/profiles.py`、`app/integrations/modbus/profiles/sdm120.yaml`、`scripts/modbus_cli.py`；`modify requirements.in`/`requirements.txt`（加 `pymodbus`、`PyYAML`，重新锁定）；`create tests/test_modbus_driver.py`、`tests/test_modbus_profiles.py`、`tests/test_modbus_cli.py`
+- **Steps**:
+  1. `driver.py`：`read_blocks(host, port, unit_id, blocks) -> dict[int,int]`（按 profile 的 blocks 块读 input registers，FC04），用 `ModbusTcpClient`；超时/连接失败抛明确异常；大端 float32 解码 helper（`registers_to_float`，高寄存器在前）。framer 选择留可配置/可探测。
+  2. `profiles.py`：定义 pydantic `ModbusProfile` / `MetricSpec`（`key`/`address`/`type`/`unit`/`device_class`/`state_class`?/`ha_component`）；`load_profile(name) -> ModbusProfile`（读 `profiles/<name>.yaml`，校验失败抛错）；`decode(profile, registers) -> dict[key -> value]`（按各 metric 的 address+type 从寄存器对解码）；`list_profiles() -> list[(name, description)]`。**不做抽象基类/继承**，全是数据 + 模块函数。
+  3. `profiles/sdm120.yaml`：按 §3.1 示例写全核心量（参考文档 §4 地址）。
+  4. `scripts/modbus_cli.py`：纯命令行、**不依赖 DB / 不需先配设备**，供**受控手工测试**（设备接市电、非随时在线，不进自动化）。两个**只读**子命令：
+     - `read --host H --port P --unit U --profile sdm120`：按 profile 读一次、解码后**把各工程量打印成可读结果**（表格/JSON）——验证整套解码链路。
+     - `probe --host H --port P --unit U --fc 4 --address 0x0000 --count 2 [--decode float32]`：**手工指定要发送的请求内容**（功能码 FC03/04 + 起始地址 + 数量），打印**原始寄存器（hex）+ 可选大端 float 解码**——first-contact 验证网关连通、framer 模式与 unit 地址，可单读一个寄存器，不依赖 profile。
+     连接失败给清晰报错 + 非零退出。**只读**：CLI 仅暴露读功能码（FC03/04），**不提供任何写寄存器子命令**（数据红线 + 防改坏电表通信参数）。
+- **Out of scope / 不要碰**: 不连真实硬件（单测用 mock/fake 返回已知寄存器字节）；不写调度（T04）；不写电表配置寄存器；不在 profile 里放 unit_id/friendly_name。
+- **Acceptance criteria**:
+  - [ ] 单测：给定 `0x4366,0x3334` 解码为 `230.2`（参考文档实例）；字序/字节序正确。
+  - [ ] 单测：`load_profile("sdm120")` 校验通过；`decode(profile, ...)` 把已知寄存器映射到正确 key 与值。
+  - [ ] 单测：profile YAML 缺字段/类型错时 `load_profile` 抛可识别校验错。
+  - [ ] 连接失败/超时抛可识别异常，不静默返回错值。
+  - [ ] `python -m scripts.modbus_cli read ...` 能（对 mock/真实网关）打印解码后的各工程量；连接失败非零退出。
+  - [ ] `python -m scripts.modbus_cli probe --fc 4 --address 0x0000 --count 2 ...` 能打印原始寄存器与可选解码值；CLI **无任何写寄存器子命令**。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 解码确为大端、高寄存器在前；地址与参考文档一致；**CLI 与 driver 都无任何写寄存器路径（仅 FC03/04）**；profile 纯协议知识、无部署项；`requirements.txt` 已同步锁定 `pymodbus`、`PyYAML`。
+
+### M5-T04 — 采集 service + APScheduler 轮询
+- **Status**: `done` · **Depends**: M5-T03
+- **Context**: 周期扫所有 enabled 设备，调用 driver 读+解码，落 `modbus_reading.payload`。仿 public-ip 的同步 job 模式。
+- **Files**: `create app/services/modbus_poll.py`；`modify app/main.py`（lifespan 注册 job）；`create tests/test_modbus_poll.py`
+- **Steps**:
+  1. `modbus_poll.py`：`poll_device(session, device) -> ModbusReading | None`（`load_profile` → driver 读 → `decode` → 把 dict 存进 `payload` 插一行；更新 `last_poll_at`/`last_poll_ok`）；`poll_all_enabled_devices(session)` 遍历 enabled 设备；service 内吞异常并日志，不让 job 崩。
+  2. `main.py`：加同步 wrapper `_run_scheduled_modbus_poll`（自管 session），`add_job(IntervalTrigger(seconds=...), id="modbus-poll", max_instances=1, coalesce=True)`。周期取**最小 per-device interval 或一个基础 tick**（实现可用单一基础 tick + 各设备按自身 interval 取模决定本 tick 是否读，保持 job 简单）；受全局 `MODBUS_POLLING_ENABLED` 控制。
+  3. 失败的设备记 `last_poll_ok=false`（供 T11 暴露），不影响其它设备。
+- **Out of scope / 不要碰**: 不发 MQTT（T11）；不加 HTTP 路由（T05）；不引入两级周期（后续杠杆）。
+- **Acceptance criteria**:
+  - [ ] 单测：mock driver 返回已知 dict，`poll_all_enabled_devices` 后 `modbus_reading` 精确 +N 行、`payload` 内容正确。
+  - [ ] 单测：某设备读失败时其它设备仍正常落库，job 不抛；失败设备 `last_poll_ok=false`。
+  - [ ] `MODBUS_POLLING_ENABLED=false` 时不轮询。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: session 在 wrapper 内开关、try/finally 关闭；job `max_instances=1` 防叠加；无 N+1/每行单独 connect 的明显低效；异常不外泄崩 job；payload 为解码后的 dict（非裸寄存器）。
+
+### M5-T05 — Modbus JSON API（device CRUD + readings + metrics + test）
+- **Status**: `done` · **Depends**: M5-T02
+- **Context**: 给前端提供设备 CRUD、最新读数、时间范围读数、量目录、即时试读。
+- **Files**: `create app/api/routes/api/modbus.py`、`app/schemas/modbus.py`；`modify app/main.py`（注册路由）；`create tests/test_api_modbus.py`
+- **Steps**:
+  1. devices：`GET`(list)/`POST`/`GET{uuid}`/`PATCH{uuid}`/`DELETE{uuid}`；session+CSRF；`POST` 校验 profile 名存在；`DELETE` 有读数 → 409。
+  2. readings：`GET {uuid}/latest`（最新一行 payload）、`GET {uuid}/readings`（`start/end/limit`，limit 有上限防全表导出，按 `recorded_at` 升序，返回 `recorded_at + payload`）。
+  3. `GET {uuid}/metrics`：返回该设备 profile 的量目录（key/label/unit/device_class），供前端渲染。
+  4. `GET /api/modbus/profiles`：`list_profiles()` 的名+描述。
+  5. `POST {uuid}/test`：用 driver 即时读一次返回解码 payload（或错误），**不落库**。
+- **Out of scope / 不要碰**: 不在此处发 MQTT；不写采集逻辑（复用 T03/T04 的 driver/service）。
+- **Acceptance criteria**:
+  - [ ] CRUD 行为正确：创建/改/删行数精确；删有读数的设备返回 409；未登录 401、缺 CSRF 403；建设备引用不存在 profile → 422。
+  - [ ] readings 时间范围 + limit 上限生效；latest 返回最新一条 payload；metrics 返回 profile 量目录。
+  - [ ] schema 经 OpenAPI 固化入库。
+  - [ ] 校验闸门全绿（含 `openapi/` 重导出）。
+- **Reviewer checklist**: 删除受 RESTRICT 保护、无批量删/清表路径；查询走 `(device_id, recorded_at)` 索引；test 端点确不落库；路径键用 `uuid`。
+
+### M5-T06 — 前端：设备管理 UI（Energy 视图）
+- **Status**: `done` · **Depends**: M5-T01, M5-T05
+- **Context**: 在侧栏加 Energy 入口与 `/energy` 路由；设备增删改 + 试读。
+- **Files**: `create frontend/src/pages/EnergyPage.tsx`、`frontend/src/energy/DeviceForm.tsx`、`frontend/src/energy/hooks.ts`；`modify frontend/src/App.tsx`（路由）、`frontend/src/components/AppSidebar.tsx`（Energy 项）；`create` 对应 `*.test.tsx`
+- **Steps**: `useQuery`/`useMutation` 接 `/api/modbus/devices` API；列表 + 新建/编辑表单（friendly_name/host/port/unit_id/profile 下拉/poll/enabled）+ 删除二次确认（删失败 409 提示改用禁用）；"试读"按钮调 `POST {uuid}/test` 显示结果。
+- **Out of scope / 不要碰**: 走势图在 T07；不碰其它页面。
+- **Acceptance criteria**:
+  - [ ] 能增/改/删设备并即时刷新；删除有二次确认；409 有友好提示；profile 走 `/api/modbus/profiles` 下拉。
+  - [ ] 侧栏出现 Energy 入口、`/energy` 可达。
+  - [ ] 前端闸门全绿。
+- **Reviewer checklist**: 全部走生成的类型化 client；删除走确认；无与契约不符的手写请求。
+
+### M5-T07 — 前端：读数展示 + Recharts 走势图
+- **Status**: `done` · **Depends**: M5-T05（数据）, M5-T06（页面壳）
+- **Context**: 在 Energy 页展示每设备最新读数 + 时间序列走势。
+- **Files**: `modify frontend/src/pages/EnergyPage.tsx`；`create frontend/src/energy/EnergyCharts.tsx`（封装 Recharts）；`modify frontend/package.json`（加 `recharts`，`package-lock.json` 同步）；`create` 对应测试
+- **Steps**: 最新读数卡片（接 `latest`，字段标签/单位取自 `/metrics`）；时间范围选择 + 折线图（电压/电流/功率/电能，从 `payload` 按 key 取序列），接 `readings`（窗口 + limit）；图表封在 `EnergyCharts` 内（仿 Leaflet 隔离，便于将来换库）。
+- **Out of scope / 不要碰**: 不做服务端降采样（后续）；不改后端。
+- **Acceptance criteria**:
+  - [ ] 最新读数与走势图渲染正确；时间范围只取窗口数据（不拉全量）；标签/单位来自 metrics。
+  - [ ] Recharts 封装自包含、仅此处 import。
+  - [ ] 前端闸门全绿（`build` 通过，注意 chunk 体积提示）。
+- **Reviewer checklist**: 图表组件隔离；查询有窗口/上限；空数据/加载/错误态有处理；从 payload 取 key 的逻辑容忍缺 key。
+
+### M5-T08 — MQTT / Discovery 配置项（CONFIG_FIELDS）
+- **Status**: `done` · **Depends**: none
+- **Context**: 把 MQTT broker 与 discovery 的标量配置接入扁平配置系统（前端自动渲染）。
+- **Files**: `modify app/config.py`（新增 Settings 字段）、`app/services/config_page.py`（追加 CONFIG_FIELDS + `_settings_payload`）；`modify .env.example`；`modify tests/test_api_config.py`
+- **Steps**: 加字段 `mqtt_enabled`、`mqtt_broker_host/port/username/password`(secret)、`mqtt_tls_enabled`、`ha_discovery_enabled`、`ha_discovery_prefix`(默认 `homeassistant`)、`modbus_polling_enabled`；CONFIG_FIELDS 归入「MQTT」「Home Assistant Discovery」「Modbus」section；`_settings_payload` 补齐对应行。
+- **Out of scope / 不要碰**: 不建 MQTT 客户端（T10）；不动 expose 表（T09）。
+- **Acceptance criteria**:
+  - [ ] 新配置项在 `GET /api/config` 出现且分 section；password 为 secret（回空、留空保留）；port 为 number。
+  - [ ] 非法值（端口非数字）422 不写库。
+  - [ ] 校验闸门全绿（OpenAPI 若变化则重导出）。
+- **Reviewer checklist**: secret 不回显/不入 OpenAPI 示例；`_settings_payload` 未漏字段（否则运行期 override 丢失）。
+
+### M5-T09 — `exposed_entities` 表 + ExposableEntity/provider 框架 `[schema]`
+- **Status**: `done` · **Depends**: M5-T02
+- **Context**: 建"可暴露实体目录"的抽象与开关存储；modbus provider 把设备映射成 device/entities，**实体元数据从 profile 派生**。
+- **Files**: `create app/integrations/expose.py`（`ExposableEntity`、provider 协议、注册表、modbus provider）；`create app/models/expose.py`（`ExposedEntityToggle`：`key` unique + `enabled` + `updated_at`）；`create alembic_app/versions/<date>_08_exposed_entities.py`；`modify alembic_app/env.py`、`scripts/app_db_adopt.py`；`create tests/test_expose_catalog.py`
+- **Steps**:
+  1. `ExposableEntity`（`key/component/device/device_class/unit/value_getter`）+ provider 接口 `enumerate(session) -> list[ExposableEntity]`。
+  2. modbus provider：每个 enabled 设备 → 一个 device（`identifiers` 用设备 `uuid`），其各量 → sensor entity（**device_class/unit/component 取自 profile 的 `metrics[]`**），加一个 `binary_sensor` online（取 `last_poll_ok`）。
+  3. `build_catalog(session)` 合并所有 provider 的实体 + 各自 `enabled`（来自 toggle 表，缺省 false）。
+  4. migration 建 toggle 表；更新 baseline 常量。
+- **Out of scope / 不要碰**: 不发 MQTT（T11）；不加 HTTP（T12）。
+- **Acceptance criteria**:
+  - [ ] 单测：建若干设备后 `build_catalog` 产出每设备对应 entity（含 online binary_sensor）+ 正确 device 分组、device_class、unit（与 profile 一致）。
+  - [ ] toggle 表 migration 可升/降；缺省 enabled=false。
+  - [ ] 至少含一个非 sensor component（online binary_sensor）。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: `key` 稳定（用设备 `uuid` + 量 key，不用自增 id，避免重建漂移）；component 支持多类型；目录由 provider 计算、元数据源自 profile 而非写死。
+
+### M5-T10 — MQTT 客户端（paho，lifespan 连接 + 重连）
+- **Status**: `done` · **Depends**: M5-T08
+- **Context**: 长连接 MQTT 客户端，配置变更可重连；含连接测试端点。
+- **Files**: `create app/integrations/mqtt.py`；`modify app/main.py`（lifespan 起/停）、`app/api/routes/api/config.py`（`POST /api/config/mqtt/test`）；`modify requirements.in`/`requirements.txt`（加 `paho-mqtt` 重新锁定）；`create tests/test_mqtt_client.py`
+- **Steps**:
+  1. `MqttManager`：`is_configured()`、`connect()/disconnect()/reconnect(settings)`、`publish(topic, payload, retain)`；paho `loop_start()` 后台线程；未配置/未启用则 no-op。
+  2. lifespan：启用则 connect；shutdown disconnect。
+  3. 配置保存后若 MQTT 设置变化 → 触发 manager 重连（在 config 保存路径加 hook 或保存后比对）。
+  4. `POST /api/config/mqtt/test`：用提交/现存配置试连**并发布一条测试消息**到一个测试 topic（如 `<discovery_prefix>/home-automation/test`），返回三态（success/config-error/failed）。仿 SMTP 测试"发一封测试邮件"的语义——用户随后在 **MQTT Explorer** 里就能看到这条消息，确认 broker 发布链路通（这是 MQTT 端的手工验证手段，**不另做 CLI**）。
+- **Out of scope / 不要碰**: 不构建 discovery/state 消息（T11）。
+- **Acceptance criteria**:
+  - [ ] 单测（fake broker/paho mock）：configured 时 connect 调用正确；未配置 no-op；publish 透传 topic/payload/retain。
+  - [ ] `POST /api/config/mqtt/test` 试连**并发布一条测试消息**（可在 MQTT Explorer 看到）；三态有明确返回；session+CSRF 保护。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 断网/连接失败不崩主进程；线程在 shutdown 正确停止；`requirements.txt` 同步锁定 `paho-mqtt`；密码不进日志。
+
+### M5-T11 — Discovery 发布 + state 发布
+- **Status**: `done` · **Depends**: M5-T09, M5-T10
+- **Context**: 把 enabled 实体发成 HA discovery config（retained）并周期推 state；采集轮询后推最新值。
+- **Files**: `create app/services/ha_discovery.py`；`modify app/services/modbus_poll.py`（轮询后推 state）、`app/main.py`（state 周期 job + 连接后/勾选变更后发 discovery）、`app/api/routes/api/...`（`/api/expose/republish` 在 T12 接，本任务提供 service）；`create tests/test_ha_discovery.py`
+- **Steps**:
+  1. `build_discovery_payload(entity)` → HA 规范 config（`<prefix>/<component>/<node>/<object>/config`，含 `device` 块、`state_topic`、`device_class`、`unit_of_measurement`、`availability`；**`unique_id` 用设备 uuid + 量 key 派生，`name` 用 friendly_name**）。
+  2. `publish_discovery(session)`：对 enabled 实体发 retained config；对取消勾选的发空 payload 清除。
+  3. `publish_states(session)`：取各实体当前值发 state；采集在 `poll_device` 成功后顺带推该设备实体 state + online。
+  4. lifespan：连接成功 / 目录或勾选变更后 `publish_discovery`；周期 job 兜底 `publish_states` + availability。
+- **Out of scope / 不要碰**: 不做前端（T12）；不改采集解码逻辑。
+- **Acceptance criteria**:
+  - [ ] 单测：discovery payload 符合 HA 结构（device 分组正确、topic/device_class/unit 正确、`unique_id` 取自 uuid）；取消勾选发空 payload。
+  - [ ] 单测：采集轮询成功后推对应 state topic；失败推 online=false。
+  - [ ] discovery 用 retained。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 仅发 enabled 实体；entity `unique_id` 稳定（源自 uuid，不随改名变）；MQTT 未启用时整链 no-op；不阻塞轮询。
+
+### M5-T12 — 前端：Expose 勾选 UI + `/api/expose`
+- **Status**: `done` · **Depends**: M5-T09, M5-T11
+- **Context**: 后端 expose 读写端点 + 设置页勾选界面。
+- **Files**: `create app/api/routes/api/expose.py`、`app/schemas/expose.py`；`modify app/main.py`；`create tests/test_api_expose.py`；前端 `create frontend/src/pages/.../ExposeSettings.tsx`（或并入 ConfigPage）、`modify` 路由/设置入口；`create` 前端测试
+- **Steps**: `GET /api/expose`（目录 + 勾选 + MQTT/Discovery 状态）、`PUT /api/expose`（key→bool）、`POST /api/expose/republish`（调 T11 service）；前端列出目录、按 device 分组、逐项开关、显示连接状态、"重新发布"按钮。
+- **Out of scope / 不要碰**: 不改采集/发布逻辑（T11）。
+- **Acceptance criteria**:
+  - [ ] `GET/PUT /api/expose` 正确读写勾选；session+CSRF；OpenAPI 固化。
+  - [ ] 勾选变更后（或点重新发布）触发 discovery 重发。
+  - [ ] 前端能勾选并显示状态；前后端闸门全绿。
+- **Reviewer checklist**: PUT 只改 toggle 不误碰其它配置；republish 真触发 T11；类型化 client。
+
+### M5-T13 — 文档 + OpenAPI + roadmap 收尾
+- **Status**: `done` · **Depends**: 全部
+- **Files**: `modify README.md`（Modbus/Energy/MQTT 段、新依赖）、`docs/roadmap.md`（M5 行 + 把"MQTT/IoT"从"下一阶段"毕业、新增 Modbus 采集方向）、`docs/architecture-overview.md`（新增 MQTT 通道与 Modbus 采集）；`modify docs/design/README.md`（列入 m5）；`run python scripts/export_openapi.py` 并提交 `openapi/`
+- **Acceptance criteria**:
+  - [ ] 文档反映新链路；`git diff --exit-code openapi/` 无未提交差异。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 无残留旧描述（含旧 `energy_meters`/`/api/energy` 字样）；OpenAPI 已入库。
+
+---
+
+## 8. 前端校验闸门（前端任务每次结束都要全绿）
+
+在 `frontend/` 下：
+```bash
+npm ci
+npm run lint
+npm run typecheck
+npm run test
+npm run build        # 必须产出 dist；留意 chunk 体积告警
+```
+- 后端若同任务改了路由/schema，仍需根目录 `python scripts/export_openapi.py` 并提交 `openapi/`。
+- 新增前端依赖（recharts）须提交 `package.json` + `package-lock.json`。
+
+## 9. 构建上下文完整性（M1 教训）
+
+- 本里程碑**不删/移文件**，但新增了 Python 依赖（`pymodbus`、`PyYAML`、`paho-mqtt`）与前端依赖（`recharts`）：必须同步 `requirements.in/.txt` 的重新锁定与 `package-lock.json`，否则镜像构建会缺包。
+- 新增源文件都在 `app/`、`scripts/` 与 `frontend/` 既有 COPY 范围内，无需改 `Dockerfile` 的 `COPY`；**但 `app/integrations/modbus/profiles/*.yaml` 是非 .py 资源**——确认 `COPY app ...` 把整个目录（含 YAML）带进镜像，且运行期能按相对路径定位 YAML（建议用 `importlib.resources` 或基于 `__file__` 的路径，别用 CWD 相对路径）。`scripts/modbus_cli.py` 须在镜像里可 `python -m scripts.modbus_cli` 调用；`tests/test_deployment.py::test_dockerfile_copy_sources_exist` 仍应通过。
+- 发版前置走查（见 CLAUDE.md）：真起 app 跑一次轮询、真连一次 broker、前端 Energy 视图人工瞄一眼渲染，再打 tag。
+
+## 10. 后续杠杆（本里程碑不做，文档留痕）
+
+- **热点量的 generated column + 索引**：JSON `payload` 默认无法对单个量建索引；某个量若需高频聚合，给 `modbus_reading` 加一列 `GENERATED ALWAYS AS (json_extract(payload,'$.<key>'))` 并建索引——非破坏性、要哪个补哪个。
+- **两级采样周期**：瞬时量（V/I/P/PF/Hz）快、累计电能慢——9600 总线吃紧或要把功率压到 5s 以下时再开（device 表加 `slow_interval_s`，读数表是通用 payload、无需改结构）。
+- **保留 / 降采样**：5s 采样长期行数大（≈630 万行/年/设备），加定期降采样或保留窗口任务（独立于本里程碑），`GROUP BY` + `AVG(json_extract(...))` 在 SQL 端做。
+- **更多 device profile**：三相电表（如 SDM630）新增一个 YAML profile（payload 里多几个相位 key），不改表、不改采集主链。
+- **更多 expose provider**：public-ip / poo 等挂入 expose 框架。
+- **写 Modbus 寄存器**：当前只读；如需经 MQTT/UI 控制设备（switch 类），再单独评估安全边界。
+
+## 11. 人工验收 walkthrough（实现完成后）
+
+> 重点：用命令行**手工**读到设备数据并展示结果。这些是**受控手工测试**——设备接市电、并非随时在线，故**不纳入自动化测试**（自动化只用 mock）；CLI 工具（`modbus_cli read/probe`）就是为这种"我想测的时候手动测一次"而设。可用 `docker compose` 起环境，命令在容器内或容器外跑均可。
+
+**前提**：网关（Waveshare RTU↔TCP）已上电接入网络，电表 Meter ID 已知（默认 1）。
+
+**1) 命令行直接试读（不依赖 DB，最快验证）**
+- 容器内：`docker compose exec <app> python -m scripts.modbus_cli read --host <网关IP> --port 502 --unit 1 --profile sdm120`
+- 或容器外：`source .venv/bin/activate && python -m scripts.modbus_cli read --host <网关IP> --port 502 --unit 1 --profile sdm120`
+- 预期：打印解码后的工程量（电压/电流/有功功率/功率因数/频率/导入导出电能等），数值合理；连不上则清晰报错。
+- **first-contact / 原始验证**：`python -m scripts.modbus_cli probe --host <网关IP> --port 502 --unit 1 --fc 4 --address 0x0000 --count 2 --decode float32` —— 手工指定请求内容、看原始回复（电压寄存器应解出约 230V），用于确认网关 framer 模式与 unit 地址；建 profile / 设备前就能跑。
+
+**2)（可选）经 API 试读已配置的设备**
+- 先在前端 Energy 页或 `POST /api/modbus/devices` 建一个设备；
+- `POST /api/modbus/devices/{uuid}/test` 即时试读，返回解码 payload（不落库）。
+
+**3)（可选）验证后台轮询落库**
+- 确认 `MODBUS_POLLING_ENABLED=true` 且设备 `enabled`；等一个采样周期；
+- 看前端 Energy 视图的最新读数/走势图，或查 `GET /api/modbus/devices/{uuid}/readings` 有新行。
+
+**4)（可选）手工验证 MQTT / HA Discovery 发布链路**（受控手工步骤，不进自动化）
+- **broker 发布链路**：配好 MQTT broker 后，在 Config 页点「发送测试消息」（`POST /api/config/mqtt/test`）——它试连并发一条测试消息；打开 **MQTT Explorer** 确认能收到，即链路通。
+- **HA Discovery**：在 Expose 设置勾选若干实体、开 `HA_DISCOVERY_ENABLED`，点「重新发布 discovery」（`POST /api/expose/republish`）；到 **Home Assistant** 确认对应 device/entity 出现、值正确。
+- **改名验证**：改某设备 friendly_name 后重发，确认 HA 显示名跟着变、历史不丢（`unique_id` 稳定）。
+- 不通则按需调整配置/勾选再重发即可。
+
+## 12. 里程碑完成定义（DoD）
+
+- 后端能按 per-device 周期静默轮询 Modbus-TCP 设备、按 YAML profile 解码落 `modbus_reading.payload`，支持多设备 CRUD。
+- MQTT 启用时，勾选的实体以 HA Discovery 注册成 device/entities（含非 sensor），state 周期发布；配置变更可重连重发；改 friendly_name 重发后 HA 显示名跟着变、`unique_id` 不变。
+- 前端侧边栏可切换功能；Energy 视图能管理设备、看最新读数与走势图；设置页可勾选 expose。
+- 后端 `pytest`/`ruff`/`export_openapi` + 前端 `lint/typecheck/test/build` 全绿且 `openapi/` 已入库。
+- README / architecture / roadmap / design 索引反映 M5 现实。
@@ -0,0 +1,483 @@
+# M6 — 通用电价层 + DSMR 实时数据 → 实时买卖电费计算（含 Tibber 动态 / 固定合同两种 profile）
+
+> 阅读前提：先读 [`README.md`](./README.md)（协作模型、任务卡格式、校验闸门、数据安全红线）。本里程碑建立在 **M5（MQTT + HA Discovery + expose 框架 + Energy 视图 + Recharts）** 之上，复用其大部分基建，并把 M5 的"两层模型"（YAML profile 定结构 + DB 行存部署值）从设备采集复制到**电价合同**上。
+> **状态**：架构与原子任务已拆到可开工。少数价格常数（卖价残差、能源税年值、双费率寄存器映射）等真实 Tibber token / 账单确认，已落成 §13 的可调值 + TODO，不阻塞实现。
+
+## 1. 目标
+
+把"电价合同"与"DSMR 实时电表数据"接起来，按 **15 分钟**周期算出**实际买电支出 / 卖电收入**，自己落库留底（不可变、可审计），并通过 MQTT + HA Discovery 反哺 Home Assistant 的 Energy 仪表盘：
+
+1. **通用电价层（两层模型）**：仓库内**只读 YAML profile 定义合同结构**（`manual` 固定/可变费率、`tibber` 动态电价各一个结构）；DB 的 **`EnergyContract`（+ 版本）存可改的数值**（UI 填）；**price strategy** 按 `kind` 出价。一次激活一个合同。
+2. **DSMR 实时数据接入**：订阅 DSMR Reader 的 `dsmr/json`（每秒一条完整 telegram），**整帧存为 JSON blob、按 10 秒降采样**落库（电、气、各相全存，未来加供暖不改表）。
+3. **实时买卖电费计算（两层）**：每 15 分钟用**电表累计寄存器差值** × 当时合同的买/卖价算计量电费（不可变、快照价）；日/月/年**汇总**再加固定费、减能源税抵扣。**不做净计量**（saldering 2027 取消）。
+4. **反哺 Home Assistant**：复用 M5 expose/Discovery，把当前买/卖价、累计买电支出、累计卖电收入发成 HA 实体（累计用 `total_increasing`）。
+5. **前端**：Energy 视图下新增合同管理（按 profile 结构生成表单）+ 价格曲线 + 费用走势/明细 + Tibber 测试。
+
+> **命名分层（延续 M5）**：存储/采集/计算层中性命名（`dsmr_*` / `tibber_price` / `energy_cost_period` / `energy_contract`）；面向用户并入既有 **Energy** 视图。
+
+## 2. 现状（实现者可据此工作，不必通读全仓库）
+
+**单库 + Alembic（M5 完成态）**
+- `app/db.py`：`class Base(DeclarativeBase)`，cached engine（已开 `journal_mode=WAL` + `foreign_keys=ON`）。
+- 单 Alembic 链 `alembic_app/`，**当前 head = `20260622_10_exposed_entities`**；`scripts/app_db_adopt.py` 的 `APP_BASELINE_REVISION` 同。迁移命名 `YYYYMMDD_NN_<desc>.py`，串 `down_revision`；`alembic_app/env.py` 逐个 import 模型。
+- `modbus_reading` 已确立**通用 JSON payload 遥测**范式（`recorded_at` 真实索引列 + `payload` JSON）——`dsmr_reading` 直接沿用。
+- M5 两层模型（`app/integrations/modbus/profiles/*.yaml` 定结构 + `modbus_device` 存部署值 + pydantic 启动期校验 + `decode`）是本里程碑电价层的范本。
+
+**配置系统（扁平 KV，自动渲染）**
+- `app/config.py` `Settings(BaseSettings)`；`app/services/config_page.py` 的 `CONFIG_FIELDS` 注册表 + `build_runtime_settings(session, bootstrap)`（DB override 合并，**消费方都用它**）+ `_settings_payload`（新字段补一行）。前端 `ConfigPage.tsx` 按 section/`input_type`/`secret` 通用渲染，bool 渲染成开关。
+- ⚠️ 扁平 KV **装不下"合同清单 + 逐字段数值 + 版本"**——这些走专用表 + 专用 API + 自定义 UI（仿 M5 `modbus_device`）。
+
+**MQTT（M5，关键：当前只发不收）**
+- `app/integrations/mqtt.py` `MqttManager`：`is_configured/is_connected/connect/disconnect/reconnect/publish`，paho `loop_start()` 后台线程，VERSION2 回调。**无 `subscribe`/`on_message`**——M6-T06 在此扩订阅端。
+- `app/integrations/expose.py`：`ExposableEntity`（dataclass，`value_getter: Callable[[Session],Any]`）、`EntityProvider = Protocol(session)->list[ExposableEntity]`、`register_provider` + `build_catalog`。已有 `_modbus_provider`。**M6 加 `_energy_cost_provider` 复用整条 Discovery 链**。
+- `app/services/ha_discovery.py`：`build_discovery_payload`/`publish_discovery`/`publish_states`/`publish_device_state`。`app/models/expose.py` `ExposedEntityToggle`（默认未勾不暴露）。
+
+**后台调度（APScheduler，UTC）**
+- `app/main.py` lifespan：`BackgroundScheduler(timezone="UTC")`，`add_job(..., max_instances=1, coalesce=True)`；同步 wrapper 自管 session、吞异常不崩 job。已有 public-ip / modbus-poll / discovery-state 等 job——**新增 job/订阅不得破坏它们**。
+
+**依赖**：`httpx`（Tibber GraphQL）、`paho-mqtt`、`pyyaml`、`apscheduler` 均已在 `requirements.in/.txt`。**M6 不新增 Python 依赖**。前端已有 Recharts / TanStack Query / `openapi-fetch` 类型化 client / Mantine。
+
+## 3. 目标架构
+
+### 3.0 数据流总览
+
+```
+ EnergyContract(active, 版本带生效日期)         DSMR Reader
+   │  kind=manual → 常数双费率                    │ MQTT dsmr/json (1s)
+   │  kind=tibber → API 15min                     ▼
+   │                                    订阅 + 10s 降采样 → dsmr_reading(整帧 JSON blob)
+   │ (kind=tibber 时)                              │
+   ▼                                               │ 累计寄存器=真值
+ Tibber GraphQL → tibber_price(15min, 不可变)      │
+   │                                               ▼
+   └──────────────► price strategy ◄────── 计费引擎（每 15min 边界）
+                   (manual/tibber 出价)            │ 寄存器差 × 价，快照
+                                                   ▼
+                                       energy_cost_period(每15min 计量电费, 不可变)
+                                                   │
+                          ┌────────────────────────┼───────────────────────────┐
+                          ▼                         ▼                            ▼
+              日/月/年汇总(+固定费 −抵扣)   expose provider + HA Discovery   /api/energy/* + 前端
+```
+
+三条核心原则：
+1. **算钱用寄存器差值，不用功率积分**：每 15 分钟能量 = 累计寄存器@末 − @初，电表真值、与采样频率无关。瞬时功率只用于显示（且 HA 里已有，后端不专门用它算钱）。
+2. **结构固定（YAML）、数值可改（UI/DB）、历史不可变（快照 + 版本）**：profile YAML 定合同长什么样；UI 填数值、改价存新版本；算过的周期快照当时的价，永不被回改。
+3. **两层费用**：每 15 分钟只算**计量电费**；按天/年的**固定费、能源税抵扣**在**汇总层**加，不污染每周期引擎。三相 / 双费率 / 燃气都靠"通用 blob + profile 结构"容纳，不改表。
+
+### 3.1 两层电价模型（本里程碑地基，仿 M5）
+
+```
+┌──────────────────────────────────────────────────────────────┐
+│ 知识层（固定，随代码走）          部署层（可改，落 DB，UI 填）  │
+│ ── pricing profile YAML ──        ── EnergyContract 行 ──       │
+│ • kind=manual / tibber            • name（UI 自由填）           │
+│ • 有哪些字段、单位、计费语义      • kind（UI 选）               │
+│ • 哪些分档 / 是否动态源           • active（一次一个）          │
+│ • UI 不可编辑                     • currency                    │
+│                                   ── EnergyContractVersion ──   │
+│                                   • effective_from / to         │
+│                                   • values(JSON，符合 profile)  │
+│                                   • 改价=加新版本，旧版本保留    │
+└──────────────────────────────────────────────────────────────┘
+         │ kind 决定 strategy
+         ▼
+   price strategy（代码）: manual=常数双费率出价; tibber=读 tibber_price 出价
+```
+
+- **profile YAML（仓库内只读，定结构）**：`app/integrations/pricing/profiles/manual.yaml`、`tibber.yaml`，pydantic 启动期校验。声明该 kind **有哪些字段、单位、计费语义、哪些分档**——**不放具体数值**。
+- **`EnergyContract` 行（部署，UI 填值）**：`name`（自由填，不 hardcode "fixed"）、`kind`（UI 选）、`active`、`currency`。
+- **`EnergyContractVersion`（版本/时段，可审计）**：`effective_from`/`effective_to`(null=开口) + `values`(JSON，符合 profile 结构)。**改价 = 加一个新版本行，旧版本保留**；"2026 上半年一个价、下半年另一个价" = 同合同两个版本。引擎算某周期时挑**覆盖该时刻的版本**。
+- **price strategy（代码，按 kind）**：`manual` 用版本里的双费率常数出价；`tibber` 读 `tibber_price` + 版本里的 energy_tax/sell_adjust 出价。计费引擎对两者一视同仁。
+
+**`manual.yaml` 结构（块状、可读；值在 UI 填）**
+
+```yaml
+kind: manual
+label: 固定 / 可变费率（NL，双费率）
+energy:
+  dual_tariff: true              # 用 delivered_1/2、returned_1/2 分高低谷
+  buy:
+    normal: { unit: EUR/kWh }    # 高价档（_2）
+    dal:    { unit: EUR/kWh }    # 低价档（_1）
+  sell:
+    normal: { unit: EUR/kWh }    # 回送高价
+    dal:    { unit: EUR/kWh }    # 回送低价（现两档同价，仍分开填）
+  energy_tax: { unit: EUR/kWh }  # 能源税，加到买价上（含 VAT）
+  ode:        { unit: EUR/kWh, default: 0 }   # 现并入能源税
+standing:                        # 固定费：UI 按月填，内部摊到每天
+  network_fee:    { unit: EUR/month }
+  management_fee: { unit: EUR/month }
+credits:
+  heffingskorting: { unit: EUR/year }   # 能源税抵扣，年度，汇总时扣
+```
+
+**`tibber.yaml` 结构**
+
+```yaml
+kind: tibber
+label: Tibber 动态电价（15 分钟）
+energy:
+  source: tibber_api             # buy = total; sell = total − energy_tax − sell_adjust
+  energy_tax:   { unit: EUR/kWh }
+  sell_adjust:  { unit: EUR/kWh, default: 0 }
+standing:
+  management_fee: { unit: EUR/month, default: 5.99 }
+  network_fee:    { unit: EUR/month }
+credits:
+  heffingskorting: { unit: EUR/year }
+```
+
+> 所有金额含 VAT（用户口径）。**Tibber token** 不在合同里、走 secret config（凭据归 config）。
+
+### 3.2 DSMR 接入
+
+- **数据源**：DSMR Reader 的 **Telegram JSON**（单 topic `dsmr/json`，一条 = 一帧完整 telegram，已是解析后的表寄存器值）。**每秒一条**。
+- **整帧存 JSON blob**（沿用 `modbus_reading` payload 哲学）：**不做字段 allowlist**，整帧存下来（电、气 `extra_device_*`、各相全要）。理由：现有燃气、未来供暖、三相——blob 全装，**不改表**；读取时按 key 取。
+- **实测 JSON 的坑（已确认）**：数值是 **JSON 字符串**（`"20915.154"`）→ 计费读取时转 **Decimal**；缺测相位是 **`null`** → 视为缺测；`id`（telegram 自增）做幂等去重。
+- **降采样**：仅当 `timestamp` 秒数落在 `dsmr_sample_interval_s`（默认 10）整数倍时落盘，其余丢弃（量从 60 行/分降到 ~6 行/分；秒=00 在网格上，每个 15 分钟边界都抓得到）。
+- **订阅**：扩 `MqttManager` 订阅端（`on_connect` 里 subscribe、`topic→handler`、`on_message` 分发，handler 在网络线程内只做"解析+降采样+一次短事务"、吞异常不崩连接）。`dsmr_ingest_enabled`（默认 false，opt-in）。
+- **进口/出口总量** = `delivered_1+delivered_2` / `returned_1+returned_2`；**双费率分档** = `_1`(dal/低) vs `_2`(normal/高)（NL 惯例，§13 确认别接反）。
+- **三相 / 燃气 / 供暖**：blob 天然容纳，单相→三相只是多几个 key，不改表（详 §10）。
+
+### 3.3 Tibber 价格接入（仅 `kind=tibber` 时）
+
+- **客户端**：`app/integrations/tibber/client.py`，httpx POST `https://api.tibber.com/v1-beta/gql`，`Bearer <token>`。
+- **15 分钟查询**（introspection + demo 实证）：
+  ```graphql
+  { viewer { homes { id currentSubscription {
+      priceInfoRange(resolution: QUARTER_HOURLY, first: 96) {
+        nodes { startsAt total energy tax currency level }
+  } } } } }
+  ```
+  - `Price` 字段：`total`（=energy+tax，**全包价**，demo 已证 `total==energy+tax`）、`energy`（纯 spot ex-VAT）、`tax`、`startsAt`（含时区偏移）、`currency`、`level`。
+  - 枚举 **`PriceInfoRangeResolution`** 值 `DAILY/HOURLY/QUARTER_HOURLY`（不是 `PriceResolution`）；老的 `priceInfo.range` 已废弃。
+  - **已验证（demo key）**：返回 96 节点、间隔 15 分钟、`total==energy+tax`；老数据无真 15min 价时 API 把小时价**重复成 4 个刻钟**，当前 NL 数据则是真 15 分钟。**解析不假设固定间隔/节点数**，按 `startsAt` 逐点存。
+- **抓取调度**：启动 + 每日 job 拉「今天+明天」，按 `starts_at` **upsert** `tibber_price`（幂等）。次日价约 13:00 CET 发布 → 每日 14:00 CET（12:00 UTC）抓明天，缺失每小时重试。**仅当 active 合同 kind=tibber 且 token 存在时跑**。
+- **连接测试** `POST /api/energy/tibber/test`：拉一次 current price，三态（success 带当前价 / config-error / failed），仿 M5 `mqtt/test`。
+
+### 3.4 计费引擎（两层）
+
+**第一层 — 每 15 分钟计量电费（`energy_cost_period`，不可变、快照价）**
+- 触发：APScheduler 1 分钟 tick，找"已闭合未算"的 15 分钟周期算（也支持按区间手动重算）。
+- 单周期 `[t0,t1)`（`t1` 已过）：
+  1. 取各寄存器在 `t0`/`t1` 的值（`recorded_at ≤ 边界` 的最后一行，Decimal），算 **per-register 差**：`Δd1,Δd2,Δr1,Δr2`。
+  2. 取 active 合同**在 t0 生效的版本** + 其 strategy：
+     - `manual`：`import_cost = Δd1×(buy_dal) + Δd2×(buy_normal)`（`buy_x = energy_buy_x + energy_tax + ode`）；`export_revenue = Δr1×sell_dal + Δr2×sell_normal`。
+     - `tibber`：取覆盖 t0 的 `tibber_price`（`starts_at ≤ t0` 最近一条）；`buy = total`、`sell = total − energy_tax − sell_adjust`；`import_cost = (Δd1+Δd2)×buy`、`export_revenue = (Δr1+Δr2)×sell`。
+  3. `net_cost = import_cost − export_revenue`；**upsert** `energy_cost_period`，**快照**当时用的价 + `contract_version_id`。
+- 缺价/缺数据：跳过或标 `degraded`，留待重算。**不做净计量**（进出口分开累加）。
+
+**第二层 — 汇总（日/月/年，读时计算，不存表）**
+- `Σ 周期 net_cost`（区间内）**＋ 固定费**（`network_fee + management_fee` 按月→按天 × 天数）**− 能源税抵扣**（`heffingskorting` 按年→按天 × 天数）= **实际应付**。
+- 固定费/抵扣取 active 合同版本的值；UI 按月/按年填，引擎内部摊到每天。
+
+### 3.5 数据模型（新增 5 张表，单库 app 链）
+
+> 单一 P1 智能电表，`dsmr_reading` 不设 device 表；将来第二块表加 `source` 列即可。
+
+| 表 | 关键列 | 说明 |
+| --- | --- | --- |
+| **`dsmr_reading`** | `recorded_at`(idx)、`source_id`(unique，=telegram id)、`payload`(JSON) | 整帧 telegram blob，10s 降采样 |
+| **`energy_contract`** | `name`、`kind`(manual/tibber)、`active`、`currency`、时间戳 | 合同头；一次一个 active |
+| **`energy_contract_version`** | `contract_id`(FK)、`effective_from`、`effective_to`(null)、`values`(JSON)、`created_at` | 版本/时段；改价加新版本、旧版本保留（审计）|
+| **`tibber_price`** | `starts_at`(unique)、`resolution`、`energy`、`tax`、`total`、`level`、`currency`、`fetched_at` | 15min 价缓存，**不可变**；仅 tibber kind |
+| **`energy_cost_period`** | `period_start`(unique)、`d1/d2/r1/r2_kwh`(周期差)、`import_cost`、`export_revenue`、`net_cost`、`currency`、`pricing`(JSON 快照)、`contract_version_id`(FK)、`degraded`、`computed_at` | 每15min 计量电费，**不可变**（快照价+来源版本）|
+
+- `energy_cost_period` 存 per-register 差 + 快照价 → 完全可审计、source-agnostic、可重算覆盖。
+- FK：`energy_contract_version.contract_id → energy_contract.id`（ON DELETE RESTRICT）；`energy_cost_period.contract_version_id → energy_contract_version.id`（RESTRICT，保审计链）。
+
+### 3.6 不可变 / 审计（贯穿）
+
+1. **算账快照**：`energy_cost_period` 存死当时实际用的价 + `contract_version_id`；改合同 / 改价**不回改**已算周期——"以前的价就是以前的价"。重算是**显式 opt-in**（`POST /recompute`），不自动覆盖历史。
+2. **合同版本只增不改**：改价 = 新 `energy_contract_version`（带生效日期），旧版本保留，全程审计链。
+3. **Tibber 价不可变**：过去某 15 分钟的价不会变。
+4. 三者叠加 → manual / tibber 都满足审计与不可变。
+
+### 3.7 MQTT / HA expose（复用 M5）
+
+加 `app/integrations/expose.py::_energy_cost_provider`（`register_provider`），归一个 HA device（`identifiers="energy-cost"`）：
+
+| key | component | 取值 | 用途 |
+| --- | --- | --- | --- |
+| `buy_price_now` | sensor | 当前周期/当前档买价（€/kWh，monetary） | HA 当前单价 |
+| `sell_price_now` | sensor | 当前卖价（€/kWh） | |
+| `import_cost_total` | sensor | 累计 import_cost（`total_increasing`，monetary，currency） | HA Energy "总成本实体" |
+| `export_revenue_total` | sensor | 累计 export_revenue（`total_increasing`） | HA Energy 回送补偿 |
+
+- `value_getter(session)` 从 `energy_cost_period`（累计/当前）取值。沿用 M5 勾选（默认未勾）、`publish_discovery`、`publish_states`（计费 job 后顺带推 + 周期兜底）。
+
+### 3.8 前端（并入 Energy 视图）
+
+- **合同管理**：列表 + 新建/编辑（**表单按选中 profile 结构渲染字段**：manual 双费率/能源税/固定费/抵扣；tibber token 提示走 Config）+ 激活（一次一个 active）+ 改价=新版本（带生效日期）+ 版本历史只读展示。
+- **价格曲线**：今天+明天 15min 买/卖价（tibber）或固定档位（manual）折线（复用 `EnergyCharts`），取 `/api/energy/prices`。
+- **费用走势 + 明细 + 汇总**：当日/月 import_cost/export_revenue/net 走势 + 每 15min 明细 + 汇总卡片（含固定费/抵扣），取 `/api/energy/costs` + `/costs/summary`。
+- **Tibber 测试**：Config 页一块「Tibber」，三态（仿 MQTT 测试）。
+- 全走类型化 client；空/加载/错误态齐全；缺 key 容错。
+
+## 4. API 契约（M6 要落地的端点）
+
+> 全部 `/api` 前缀、session + CSRF（写）保护、JSON 进出；schema 经 `scripts/export_openapi.py` 固化入库。
+
+| 分组 | 端点 | 用途 |
+| --- | --- | --- |
+| 合同 | `GET /api/energy/contracts` | 列出合同 + active 标记 |
+| 合同 | `POST /api/energy/contracts` | 新建合同（kind + 首版本值，按 profile 校验）|
+| 合同 | `GET /api/energy/contracts/{id}` | 单个合同 + 版本历史 |
+| 合同 | `PATCH /api/energy/contracts/{id}` | 改名 / 激活（一次一个 active）|
+| 合同 | `POST /api/energy/contracts/{id}/versions` | 加新版本（改价，带生效日期）|
+| 合同 | `GET /api/energy/profiles` | 列出 pricing profile 结构（前端按它渲染表单）|
+| 价格 | `GET /api/energy/prices?start&end` | 区间价格点（曲线）|
+| 费用 | `GET /api/energy/costs?start&end` | 区间 `energy_cost_period`（走势/明细）|
+| 费用 | `GET /api/energy/costs/summary?start&end` | 区间汇总（计量电费 + 固定费 − 抵扣）|
+| 费用 | `POST /api/energy/costs/recompute?start&end` | 幂等重算（补数据/改价后，显式）|
+| DSMR | `GET /api/energy/dsmr/latest` | 最新 `dsmr_reading` |
+| 测试 | `POST /api/energy/tibber/test` | 试连 Tibber + 拉当前价，三态 |
+
+> DSMR/Tibber 的**标量配置 + token** 复用现有 `GET/PUT /api/config`（只加 CONFIG_FIELDS）。**价格数值全在合同里**，不进 flat config。
+
+## 5. 已锁定决策（讨论后拍板）
+
+1. **两层电价模型**：profile YAML 定结构（仓库、固定、UI 不可编辑）+ `EnergyContract`(+版本) 存数值（UI 填、版本化）+ strategy 按 kind 出价。仿 M5。
+2. **kind 不叫 "fixed"**：`manual`（人工填、可双费率、可带时段）/ `tibber`（API 动态）；合同 `name` UI 自由填。
+3. **买价**：tibber = API `total`（全包，已证 total=energy+tax）；manual = `energy_buy_档 + energy_tax`。**卖价**：tibber = `total − energy_tax − sell_adjust`；manual = `sell_档`（回送价，无能源税）。均含 VAT。
+4. **双费率**：manual 用 `delivered_1/2`、`returned_1/2` 分 dal/normal 计价（`_1`=dal/低、`_2`=normal/高）；tibber 求和、15min 价不分档。
+5. **两层费用**：每 15min `energy_cost_period` 只算计量电费（不可变、快照价）；日/月/年汇总再加固定费（按月→天）− heffingskorting（按年→天）。
+6. **回送阶梯罚金（terugleverkosten）不做**：按自然年累计、用户住不到年底算不准——不算、不记、不加功能（留痕见 §10）。
+7. **DSMR 整帧存 JSON blob**（不做字段 allowlist），10s 降采样；数值转 Decimal、null 容错、`id` 幂等。扩 `MqttManager` 订阅端。
+8. **5 张表**：`dsmr_reading`、`energy_contract`、`energy_contract_version`、`tibber_price`、`energy_cost_period`。单电表不设 device 表。
+9. **不可变 / 审计**：算账快照价 + 合同版本只增不改 + tibber 价天然不可变；重算显式 opt-in。
+10. **Tibber 用 httpx + `priceInfoRange(QUARTER_HOURLY)`**，仅 active=tibber 时抓；token 走 secret config。
+11. **复用 M5 expose/Discovery**：加 `_energy_cost_provider`；累计成本/收入用 `total_increasing` 喂 HA Energy。
+12. **前端并入 Energy 视图**：合同管理表单按 profile 结构渲染；Recharts 画价/费。
+13. **opt-in 开关**：`dsmr_ingest_enabled` 默认 false；Tibber 抓取/计费由 active 合同存在性驱动。
+14. **周期边界用 UTC 刻钟**（NL 偏移整小时，本地/UTC 重合）。**不新增依赖**。
+
+> 项目定位：个人自用、家庭特化、不开源——按单用户场景简化，不过度抽象。
+
+## 6. 任务依赖图
+
+```
+Phase A（地基）
+  M6-T01 [schema] 5 张表 + 模型 + 迁移
+  M6-T02 flat 配置（dsmr_* + tibber token/home_id）        ← 与 T01 并行
+  M6-T03 pricing profile 框架（manual.yaml/tibber.yaml + pydantic + strategy 注册表）  ← 纯模块，可早做
+
+Phase B（合同 + 数据接入）
+  M6-T04 EnergyContract CRUD + 版本 + 按 profile 校验（API）   (Depends T01,T03)
+  M6-T05 Tibber 客户端 + 抓价 service + 调度 + tibber/test     (Depends T01,T02,T03)
+  M6-T06 MqttManager 扩订阅 + DSMR ingest（blob/10s）          (Depends T01,T02)
+
+Phase C（计算 + 反哺）
+  M6-T07 计费引擎（每15min 计量 + 汇总）+ 周期 job + 重算       (Depends T01,T03,T04,T05,T06)
+   └─► M6-T08 energy_cost expose provider + state 发布          (Depends T07)
+
+Phase D（API + 前端）
+  M6-T09 Energy 数据 API（prices/costs/summary/dsmr-latest/recompute）  (Depends T05,T07)
+   └─► M6-T10 前端：合同管理 + 价格/费用视图 + Tibber 测试      (Depends T04,T09)
+
+收尾
+  M6-T11 文档 + OpenAPI + roadmap（Depends 全部）
+```
+
+`T01`、`T02`、`T03` 无前置可先开。
+
+---
+
+## 7. 原子任务（任务卡）
+
+> 后端任务沿用校验闸门（`pytest` / `ruff` / 改路由或 schema 则 `export_openapi` 重导出入库）；前端闸门见 §8。**不新增依赖**。纯新增、不删/移文件；改 `app/main.py` lifespan 时不得破坏既有 job/连接。
+
+### M6-T01 — 5 张表与模型 `[schema]`
+- **Status**: `done` · **Depends**: none
+- **Context**: 单库 app 链新增 5 张表（§3.5）。只建 schema + 模型，不写采集/计算/接口。
+- **Files**: `create app/models/energy.py`（`DsmrReading`/`EnergyContract`/`EnergyContractVersion`/`TibberPrice`/`EnergyCostPeriod`）；`create alembic_app/versions/20260623_11_energy_tables.py`；`modify alembic_app/env.py`、`scripts/app_db_adopt.py`（`APP_BASELINE_REVISION`→新 head）；`create tests/test_energy_models.py`
+- **Steps**:
+  1. 按 §3.5 定义模型（`Mapped[...]`）：`DsmrReading`（`recorded_at` idx、`source_id` unique nullable、`payload` JSON）；`EnergyContract`（`name`/`kind`/`active`/`currency`/时间戳）；`EnergyContractVersion`（`contract_id` FK RESTRICT、`effective_from`/`effective_to` nullable、`values` JSON、`created_at`）；`TibberPrice`（`starts_at` unique、`resolution`、`energy/tax/total` float、`level` nullable、`currency`、`fetched_at`）；`EnergyCostPeriod`（`period_start` unique、`d1/d2/r1/r2_kwh` float、`import_cost/export_revenue/net_cost` float、`currency`、`pricing` JSON、`contract_version_id` FK RESTRICT nullable、`degraded` bool、`computed_at`）。
+  2. 新 revision：`down_revision="20260622_10_exposed_entities"`；`upgrade()` 建 5 表 + 索引/唯一/FK；`downgrade()` 反向 drop。更新 `APP_BASELINE_REVISION`。
+- **Out of scope**: 不写客户端/采集/计费/接口；不动其它模型。
+- **Acceptance criteria**:
+  - [ ] 全新临时库 upgrade 到 head 含 5 表及约束；`downgrade -1` 干净回滚；链上单 head。
+  - [ ] FK 为 RESTRICT；唯一/索引正确；`payload`/`values`/`pricing` 为 JSON 列。
+  - [ ] `APP_BASELINE_REVISION` == 新 head。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 列/约束/FK 与 §3.5 一致；`recorded_at`/`period_start`/`starts_at` 真实索引或唯一列；`env.py` 已 import 新模型；迁移 `down_revision` 指当前真实 head；无破坏性操作。
+
+### M6-T02 — flat 配置（DSMR + Tibber 凭据）
+- **Status**: `done` · **Depends**: none
+- **Context**: DSMR 订阅设置 + Tibber 凭据接入扁平配置（前端自动渲染）。**价格数值不在这里**（在合同里）。
+- **Files**: `modify app/config.py`、`app/services/config_page.py`（CONFIG_FIELDS + `_settings_payload`）；`modify .env.example`、`tests/test_api_config.py`
+- **Steps**: `Settings` 加 `dsmr_ingest_enabled: bool=False`、`dsmr_mqtt_topic: str="dsmr/json"`、`dsmr_sample_interval_s: int=10`、`tibber_api_token: str=""`、`tibber_home_id: str=""`；CONFIG_FIELDS 归「DSMR」「Tibber」section，`tibber_api_token` 为 secret，bool=checkbox、数值=number；`_settings_payload` 补齐；`.env.example` 加注释样例（默认 off）。
+- **Out of scope**: 不建客户端/采集；不动既有字段；不放任何价格常数。
+- **Acceptance criteria**:
+  - [ ] 新项在 `GET /api/config` 分 section；token 为 secret（回空/留空保留）；非法值 422 不写库。
+  - [ ] 校验闸门全绿（OpenAPI 变化则重导出）。
+- **Reviewer checklist**: secret 不回显/不进 OpenAPI 示例；`_settings_payload` 无遗漏；默认 off。
+
+### M6-T03 — pricing profile 框架 + strategy 注册表
+- **Status**: `done` · **Depends**: none
+- **Context**: 仓库内 `manual.yaml`/`tibber.yaml` 定结构（pydantic 校验），加 price strategy 注册表（manual/tibber 出价）。纯模块，单测。
+- **Files**: `create app/integrations/pricing/__init__.py`、`pricing/profiles.py`（pydantic 模型 + `load_profile`/`list_profiles`/`validate_values`）、`pricing/profiles/manual.yaml`、`pricing/profiles/tibber.yaml`、`pricing/strategies.py`（`register_strategy`/`get_strategy`、`manual`/`tibber` 实现）；`create tests/test_pricing_profiles.py`、`tests/test_pricing_strategies.py`
+- **Steps**:
+  1. `profiles.py`：pydantic 模型描述 §3.1 结构；`load_profile(kind)`（读 YAML，校验失败抛错）；`validate_values(kind, values)`（合同数值是否符合结构）。
+  2. `profiles/*.yaml`：按 §3.1 写 manual / tibber 结构。
+  3. `strategies.py`：策略接口 `price_period(deltas, t0, values, session) -> {import_cost, export_revenue, net, pricing_snapshot}`（Decimal）：
+     - `manual`：双费率公式（§3.4），`buy_x = energy_buy_x + energy_tax + ode`、`sell_x` 直接用。
+     - `tibber`：取覆盖 t0 的 `tibber_price`，`buy=total`、`sell=total−energy_tax−sell_adjust`，进出口求和。
+- **Out of scope**: 不连真实 API（tibber 策略只读 `tibber_price` 表，由 T05 填）；不写采集/调度/接口。
+- **Acceptance criteria**:
+  - [ ] 单测：`load_profile("manual"/"tibber")` 校验通过；缺字段/类型错抛可识别错；`validate_values` 正确判合规。
+  - [ ] 单测：manual 策略双费率出价正确（`import = Δd1×buy_dal + Δd2×buy_normal` 等）；tibber 策略 `buy=total`、`sell=total−energy_tax−sell_adjust`，负 total 出口得负值。
+  - [ ] Decimal 计算无 float 误差。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: profile 纯结构、无具体数值；策略用 Decimal；进出口分开（不相抵）；tibber 价匹配用 `starts_at ≤ t0` 最近一条；无 OOP 过度抽象（数据+函数，仿 M5 profiles.py）。
+
+### M6-T04 — EnergyContract CRUD + 版本 + 校验（API）
+- **Status**: `done` · **Depends**: M6-T01, M6-T03
+- **Context**: 合同增删改、版本（改价加新版本、生效日期）、激活（一次一个）、按 profile 校验数值。
+- **Files**: `create app/api/routes/api/energy_contracts.py`、`app/schemas/energy_contract.py`、`app/services/contracts.py`；`modify app/main.py`（注册路由）；`create tests/test_api_energy_contracts.py`
+- **Steps**:
+  1. `contracts.py` service：建合同（含首版本，`validate_values` 校验）、加版本（带 `effective_from`，自动闭合上一版本 `effective_to`）、激活（把其它 active 置 false）、`active_contract_version_at(session, ts)`（取 active 合同在 ts 生效的版本）。
+  2. 路由：`GET/POST/GET{id}/PATCH{id}`、`POST {id}/versions`、`GET /profiles`（返回结构供前端渲染表单）；session+CSRF；数值不合规 422。
+- **Out of scope**: 不算费用（T07）；不发 MQTT；不写采集。
+- **Acceptance criteria**:
+  - [ ] CRUD + 版本 + 激活行为正确：新建按 profile 校验（不合规 422）；加版本自动闭合上一段；激活互斥（同时只一个 active）；`GET /profiles` 返回结构。
+  - [ ] 未登录 401、缺 CSRF 403；schema 经 OpenAPI 固化入库。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 版本只增不改（不覆盖旧版本）；激活互斥；删除受 FK RESTRICT（有版本/有费用记录不可裸删）；数值校验走 T03 `validate_values`；路径键用合同 id。
+
+### M6-T05 — Tibber 客户端 + 抓价 service + 调度 + tibber/test
+- **Status**: `done` · **Depends**: M6-T01, M6-T02, M6-T03
+- **Context**: httpx 拉 15min 价 upsert `tibber_price`；启动+每日抓（仅 active=tibber）；连接测试。
+- **Files**: `create app/integrations/tibber/__init__.py`、`tibber/client.py`、`app/services/tibber_prices.py`；`modify app/main.py`（抓价 job）；`create tests/test_tibber_client.py`、`tests/test_tibber_prices.py`
+- **Steps**:
+  1. `client.py`：`fetch_price_range(token, home_id|None) -> list[PricePoint]`（§3.3 query，httpx 超时/认证失败抛错，不假设固定节点数）；`fetch_current_price(...)`（供 test）。
+  2. `tibber_prices.py`：`refresh_prices(session, settings)`（拉今天+明天 upsert，幂等）；仅当 active 合同 kind=tibber 且 token 存在时执行。
+  3. `main.py`：同步 wrapper + `IntervalTrigger`，`max_instances=1, coalesce=True`，吞异常不崩。
+- **Out of scope**: 不算费用（T07）；不发 MQTT；test 路由在 T09（本任务备 service）。
+- **Acceptance criteria**:
+  - [ ] 单测（httpx mock）：解析返回为 PricePoint；认证失败/超时抛可识别异常。
+  - [ ] 单测：`refresh_prices` 幂等（按 `starts_at` upsert，不重复插）；非 tibber active 时 no-op。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: token 不进日志；httpx 超时；upsert 幂等；时间存 UTC；无对 `tibber_price` 的破坏性批删。
+
+### M6-T06 — MqttManager 扩订阅 + DSMR ingest
+- **Status**: `done` · **Depends**: M6-T01, M6-T02
+- **Context**: 给只发不收的 `MqttManager` 扩订阅；DSMR ingest 整帧 blob + 10s 降采样落库。
+- **Files**: `modify app/integrations/mqtt.py`（订阅注册 + on_message 分发）；`create app/services/dsmr_ingest.py`；`modify app/main.py`（启用时注册订阅）；`create tests/test_mqtt_subscribe.py`、`tests/test_dsmr_ingest.py`
+- **Steps**:
+  1. `mqtt.py`：`subscribe(topic, handler)`（`on_connect` 里对已注册 topic subscribe，`on_message` 按 topic 分发，handler 异常吞掉不崩连接）；保持既有 publish 不回归。
+  2. `dsmr_ingest.py`：`handle_message(payload_bytes, settings)`：parse JSON → 取 `timestamp`(UTC) → 降采样（`second % dsmr_sample_interval_s != 0` 丢弃）→ **整帧存 payload**（值原样/Decimal 友好）→ 短 session 写 `dsmr_reading`（`source_id`=`id`，存在则跳过）。
+  3. `main.py`：`dsmr_ingest_enabled` 时把 handler 注册到 `dsmr_mqtt_topic`。
+- **Out of scope**: 不算费用（T07）；不改既有 publish/discovery 语义；不做字段 allowlist（整帧存）。
+- **Acceptance criteria**:
+  - [ ] 单测：`subscribe` 注册后 `on_message` 分发到 handler；既有 publish 无回归。
+  - [ ] 单测：喂样本 JSON（字符串数值、null 相位），秒=00 整帧落盘、秒≠10 整数倍丢弃；同 `id` 不重插。
+  - [ ] `dsmr_ingest_enabled=false` 不订阅/不落盘。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: on_message 网络线程内只做短事务、吞异常不崩连接；整帧存（含 gas/各相）；null 容错；`source_id` 幂等；10s 降采样正确。
+
+### M6-T07 — 计费引擎 + 周期 job + 汇总 + 重算
+- **Status**: `done` · **Depends**: M6-T01, M6-T03, M6-T04, M6-T05, M6-T06
+- **Context**: 每 15min 用寄存器差 × active 合同 strategy 算计量电费（快照、不可变）；汇总加固定费 − 抵扣；周期 job + 重算。
+- **Files**: `create app/services/energy_cost.py`；`modify app/main.py`（周期 job）；`create tests/test_energy_cost.py`
+- **Steps**:
+  1. `energy_cost.py`：`register_at(session, boundary)`（取 ≤boundary 最后一行的 d1/d2/r1/r2，Decimal）；`compute_period(session, t0)`（取 active 版本 + strategy（T03/T04）→ 算 → upsert + 快照 `pricing` + `contract_version_id`，缺价/缺数据标 `degraded` 或跳过）；`compute_closed_periods(session)`；`recompute_range(session, start, end)`（幂等覆盖）；`summarize(session, start, end)`（Σnet + 固定费按天 − heffingskorting 按天，取 active 版本值）。
+  2. `main.py`：1 分钟 tick job（`max_instances=1, coalesce=True`），有 active 合同 + DSMR 数据时算；吞异常不崩。
+- **Out of scope**: 不发 MQTT（T08）；不加 HTTP（T09，备 service）；不改采集/价格抓取。
+- **Acceptance criteria**:
+  - [ ] 单测：构造 `dsmr_reading`+合同版本（manual 双费率 / tibber + `tibber_price`），`compute_period` 算出正确 cost/revenue/net，快照价 + `contract_version_id` 落库；upsert 幂等。
+  - [ ] 单测：跨价格版本时按 t0 选对版本；缺价跳过、缺读数标 `degraded`。
+  - [ ] 单测：`summarize` = Σnet + 固定费（月→天×天数）− heffingskorting（年→天×天数）。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: Decimal 算钱；寄存器差为"末−初"；进出口分开；周期边界 UTC 刻钟；快照不可变（重算才覆盖，且显式）；版本选择按 `effective_from≤t0<effective_to`；job 不崩。
+
+### M6-T08 — energy_cost expose provider + state 发布
+- **Status**: `done` · **Depends**: M6-T07
+- **Context**: 复用 M5 expose/Discovery，发当前买/卖价 + 累计成本/收入。
+- **Files**: `modify app/integrations/expose.py`（`_energy_cost_provider` + 注册）；`modify app/services/energy_cost.py` 或 `app/main.py`（算完顺带 `publish_states`）；`create tests/test_energy_expose.py`
+- **Steps**: provider 产出 §3.7 实体（`buy_price_now`/`sell_price_now`/`import_cost_total`/`export_revenue_total`），累计项 `total_increasing`+`monetary`+currency；`value_getter` 从 `energy_cost_period` 取；计费 job 后 `publish_states`。
+- **Out of scope**: 不改 Discovery 机制本身；不改采集/计费。
+- **Acceptance criteria**:
+  - [ ] 单测：`build_catalog` 含 energy_cost 实体；累计项 `total_increasing`；勾选默认未勾。
+  - [ ] 单测：`value_getter` 取到正确当前价/累计值；MQTT 未启用整链 no-op。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: `key` 稳定（固定字符串）；复用既有 provider 协议、未改其它 provider；累计 `total_increasing` 语义正确；不阻塞计费 job。
+
+### M6-T09 — Energy 数据 API
+- **Status**: `done` · **Depends**: M6-T05, M6-T07
+- **Context**: 价格/费用/汇总/最新 DSMR/重算/Tibber 测试端点（合同 CRUD 在 T04）。
+- **Files**: `create app/api/routes/api/energy.py`、`app/schemas/energy.py`；`modify app/main.py`（注册）；`create tests/test_api_energy.py`
+- **Steps**: `GET /prices`、`GET /costs`、`GET /costs/summary`、`GET /dsmr/latest`、`POST /costs/recompute`（调 T07）、`POST /tibber/test`（调 T05 client，三态）；session+CSRF；查询走索引 + 窗口/上限。
+- **Out of scope**: 不写采集/计费/发布逻辑（复用 service）。
+- **Acceptance criteria**:
+  - [ ] 各端点行为正确：窗口+limit 上限生效；recompute 幂等；tibber/test 三态；401/403 正确；schema 入库（`git diff --exit-code openapi/` 无差异）。
+  - [ ] 校验闸门全绿。
+- **Reviewer checklist**: 查询有时间窗+上限；recompute 复用 T07、无破坏删；test 不泄 token。
+
+### M6-T10 — 前端：合同管理 + 价格/费用视图 + Tibber 测试
+- **Status**: `done` · **Depends**: M6-T04, M6-T09
+- **Files**: `modify frontend/src/pages/EnergyPage.tsx`；`create frontend/src/energy/ContractManager.tsx`、`ContractForm.tsx`、`TibberPrices.tsx`、`CostView.tsx`、扩 `hooks.ts`；`modify` Config 页 Tibber 测试入口；`create` 对应 `*.test.tsx`
+- **Steps**: 合同列表/新建/编辑/激活/加版本（**表单字段按 `/profiles` 结构渲染**，manual 双费率/税/固定费/抵扣）+ 版本历史只读；价格曲线 + 费用走势/明细 + 汇总卡片；Tibber 测试三态；全走类型化 client；空/加载/错误态 + 缺 key 容错。
+- **Out of scope**: 不做服务端降采样；不改后端。
+- **Acceptance criteria**:
+  - [ ] 合同 CRUD/激活/版本可用，表单按 profile 渲染；价格/费用/汇总渲染正确；区间只取窗口；币种/单位来自 API。
+  - [ ] Tibber 测试三态可用。
+  - [ ] 前端闸门全绿（`lint`/`typecheck`/`test`/`build`）。
+- **Reviewer checklist**: 全走类型化 client；图表组件隔离复用；表单按结构渲染、不 hardcode 字段；窗口/上限；空/错/加载/缺 key 容错。
+
+### M6-T11 — 文档 + OpenAPI + roadmap 收尾
+- **Status**: `done` · **Depends**: 全部
+- **Files**: `modify README.md`、`docs/roadmap.md`（M6 行 + 毕业）、`docs/architecture-overview.md`、`docs/design/README.md`（列入 m6）；`run python scripts/export_openapi.py` 并提交 `openapi/`
+- **Acceptance criteria**:
+  - [ ] 文档反映新链路；`git diff --exit-code openapi/` 无未提交差异；校验闸门全绿。
+- **Reviewer checklist**: 无残留过时描述；OpenAPI 入库；§13 已敲定项同步回文档。
+
+---
+
+## 8. 前端校验闸门
+
+在 `frontend/` 下：`npm ci && npm run lint && npm run typecheck && npm run test && npm run build`（留意 chunk 体积告警）。后端同任务改路由/schema 仍需根目录 `export_openapi.py` 并提交 `openapi/`。**不新增前端依赖**（Recharts 已在）。
+
+## 9. 构建上下文完整性（M1 教训）
+
+- **纯新增、不删/移文件**，**不新增依赖**（httpx/paho/pyyaml 已在）。新增源文件都在 `app/`、`scripts/`、`frontend/` 既有 `COPY` 范围内，无需改 `Dockerfile`；**`app/integrations/pricing/profiles/*.yaml` 是非 .py 资源**——确认随 `COPY app` 进镜像、运行期按 `__file__`/`importlib.resources` 定位（别用 CWD 相对路径）。`tests/test_deployment.py::test_dockerfile_copy_sources_exist` 仍应通过。
+- 改 `app/main.py` lifespan 注册新 job/订阅时**不得破坏**既有 public-ip / modbus-poll / discovery job 与 MQTT 连接。
+- 发版前置走查（CLAUDE.md）：真起 app → 订到 `dsmr/json`、（合同生效后）拉一次 Tibber 价、看费用落库、前端合同/价格/费用视图人工瞄一眼，再打 tag。
+
+## 10. 后续杠杆（本里程碑不做，文档留痕）
+
+- **回送阶梯罚金（terugleverkosten）**：按自然年累计、阶梯式；本期不做。将来做就把阶梯表存进合同结构，在**年度汇总**层按 YTD 累计回送量套阶梯（不进每周期引擎）。
+- **燃气 / 区域供暖计费**：数据已在 blob 里（gas `extra_device_*`）；将来在合同结构加"商品价"+ `energy_cost_period` 加 `commodity` 维度即可，不改主链。
+- **能源税分档**：年用电跨 10000 kWh 档时税率变；现按单档配置。
+- **降采样 / 保留**：`dsmr_reading` 10s 长期行数大，加定期降采样/保留窗口任务（SQL 端 `AVG(json_extract(...))`）。
+- **价格 level 配色 / 便宜时段提示**：用 Tibber `level` 驱动前端配色与用电建议。
+- **HA 让 HA 算 vs 后端算**：当前后端算累计；也可只发买/卖价 €/kWh 让 HA Energy 自乘（实体都已具备）。
+
+## 11. 人工验收 walkthrough（实现完成后）
+
+> 受控手工验证（依赖家里 DSMR Reader + broker；Tibber 部分待合同生效），不进自动化。
+
+1. **合同（先用 manual，立即可用）**：Energy 页新建一个 `manual` 合同，按表单填双费率/能源税/固定费/抵扣，激活。
+2. **DSMR 落库**：开 `dsmr_ingest_enabled`、确认 topic；MQTT Explorer 看 `dsmr/json` 有消息；等若干 10 秒 → `GET /api/energy/dsmr/latest` 有最新整帧；`dsmr_reading` 约每 10 秒一行（整帧 blob）。
+3. **费用计算**：跨过一个整刻钟边界 → `GET /api/energy/costs` 出现该周期 import/export/cost/revenue/net（manual 双费率分档对得上手算）；`GET /costs/summary` 含固定费/抵扣；改价加新版本后旧周期不变、`POST /recompute` 才覆盖。
+4. **Tibber（合同生效后）**：建 `tibber` 合同、Config 填 token、点「Tibber 测试」三态成功；激活后抓价 → `GET /prices` 有 15min 价、费用切到动态。
+5. **反哺 HA**：Expose 勾选 energy_cost 实体、开 Discovery、重发 → HA 出现当前买/卖价 + 累计成本/收入；HA Energy 挂累计实体。
+
+## 12. 里程碑完成定义（DoD）
+
+- 后端能：订 `dsmr/json` 按 10s 整帧落库；按 active 合同（manual 双费率 / tibber 动态）每 15min 用寄存器差 × 价算计量电费（不可变、快照）；日/月/年汇总加固定费 − 抵扣；不做净计量；改价走版本、历史不回改。
+- 复用 M5 Discovery 把当前买/卖价 + 累计成本/收入（`total_increasing`）发成 HA 实体。
+- 前端 Energy 视图能管理合同（表单按 profile 渲染、激活、版本）、看价格曲线与费用走势/明细/汇总、测 Tibber。
+- 后端 `pytest`/`ruff`/`export_openapi` + 前端 `lint/typecheck/test/build` 全绿且 `openapi/` 入库。
+- README / architecture / roadmap / design 索引反映 M6。
+
+## 13. 待确认 / TODO（拿到真实 token + 账单后钉死，均已落成配置/默认值，不阻塞实现）
+
+1. **买价**：✅ tibber = API `total`（demo 已证 total=energy+tax）；manual = energy_buy_档 + energy_tax。无待办。
+2. **卖价残差（tibber）**：`sell = total − energy_tax − sell_adjust`，`sell_adjust` 默认 0（买卖费相等抵消）。真实账单确认后若有残差再调。
+3. **双费率寄存器映射**：`_1`=dal/低、`_2`=normal/高（NL 惯例）——接价前用真实数据确认别接反（差价小但要对）。
+4. **能源税年值**：manual/tibber 的 `energy_tax` 默认 ~0.1108（2026 第一档含 VAT），按当年实际值核。
+5. **Tibber 15min + 币种**：✅ 查询/分辨率已 demo 证实；仍需合同生效后用**真实 token** 确认 NL 返回真 15 分钟价 + 币种 EUR。
+6. **manual 现行数值**（你的固定合同）：normal 0.133 / dal 0.127 / 回送两档（现同价）/ 管理费 ≈€0.329/天（≈€9.87/月）/ 电网费 + heffingskorting 待填。
+</content>
@@ -0,0 +1,322 @@
+# M7 — 电表生命周期 / 换表归档（Meter epochs）
+
+> 协作格式、任务卡结构、校验闸门、数据安全红线见 [`README.md`](./README.md)，本文不再重复。
+
+## 1. 目标
+
+让计费系统正确处理**电表更换**这一**必然事件**：
+
+- 荷兰 2G 智能电表退网后，电网公司**一定**会把表换成 4G 表（同址换表）；搬家继承新表也是同类。
+- 计费是**寄存器差值（delta）模型**：每个 15 分钟周期成本 =（周期末读数 − 周期初读数）× 单价。换表后新表寄存器基数与旧表**无关**（可能更高也可能更低），若跨表算 delta 会产出**负成本或巨额假成本**。
+- 目标：引入显式的 **Meter（电表）** 概念，标记"某时刻起属于哪一块物理表"，使引擎**永不跨表算 delta**，并让累计量按表归零、历史可追溯可查。
+
+非目标（本里程碑不做，§9 留痕）：gas / 区域供暖的**计费**；"家庭(home)"分组实体；多合同时间线积分；自动识别换表（DSMR 帧无电表序列号，无法自动识别，靠用户显式声明）。
+
+## 2. 现状（实现者可据此工作，不必通读全仓库）
+
+- 计费数据模型（M6）：
+  - `dsmr_reading`：整帧 JSON，`recorded_at`(UNIQUE) 去重；含 4 个累计寄存器 `electricity_delivered_1/2`、`electricity_returned_1/2`。**帧内无电表序列号字段**。
+  - `energy_cost_period`：每 15 分钟一行，存 `d1/d2/r1/r2_kwh`(delta)、`import_cost/export_revenue/net_cost`、`pricing` 快照、`contract_version_id`、`degraded`、`computed_at`、`period_start`(unique)。
+- 计费引擎 `app/services/energy_cost.py`：
+  - `register_at(session, boundary)`：取 `recorded_at ≤ boundary` 的最近一条；有 15 分钟 staleness 护栏（超过则返回 None → 周期降级）。
+  - `compute_period(session, t0)`：取 t0/t1 两端寄存器，算 delta，按 `contract` 的 strategy 计价；缺读数→降级行(成本 0)。
+  - `compute_closed_periods` / `recompute_range`：遍历刻钟边界批量算。
+  - `summarize(session, start, end)`：聚合非降级周期电费 + 固定费/抵扣（FU10 已按本地日跨版本积分）。
+- 计价策略 `app/integrations/pricing/strategies.py`：`import_cost = Δd1×buy_dal + Δd2×buy_normal` 等，**对 delta 无任何 clamp/sanity 检查**（负 delta → 负成本，超大 delta → 巨额成本）。
+- 暴露 `app/integrations/expose.py`：累计 `import_cost_total`/`export_revenue_total` 锚点（FU11）= `max(合同最早 effective_from, 最早非降级 period_start)`；`*_today` 日归零实体（FU11）。
+- 合同 `app/services/contracts.py`：`active` 互斥 + 版本时间线 + `active_contract_version_at(ts)`（半开 `[from,to)`）。合同**不引用电表**。
+- 配置/迁移：单库 app，Alembic 链 `alembic_app/`；`PRAGMA foreign_keys=ON` 已开（`app/db.py`）。
+- 时区：FU10 的 `app/services/timezone.py`（`local_*`，可 monkeypatch）。
+
+## 3. 目标架构
+
+### 3.1 核心概念：Meter（= epoch）
+
+一条 `meter` 记录 = **一块物理电表的一段安装期** `[started_at, ended_at)`。换表 = 关闭当前 active 表（`ended_at=T`）+ 新建一条 `started_at=T` 的表。计费**永不跨 meter 算 delta**：跨表的那个周期按设计降级。
+
+- **每种 `commodity` 至多一个 active 表**（`ended_at IS NULL`）。本里程碑只 `electricity` 参与计费，`commodity` 字段为未来 gas/heating 预留。
+- `meter_at(session, ts, commodity="electricity")`：返回 `started_at ≤ ts AND (ended_at IS NULL OR ts < ended_at)` 的那块表（半开区间，仿 `active_contract_version_at`）。
+- 计费基准：某表窗口内**最早的一条 `dsmr_reading`**（`recorded_at ≥ started_at`）即基准；用户**只需填 `started_at` 日期，无需知道当前读数**。追溯（`started_at` 在过去）时，有效起点自然 = `max(started_at, 数据起点)`。
+- **隔离的前提 = 显式声明**：系统无法自动识别换表（DSMR 帧无序列号），搬家后新旧读数同落 `dsmr_reading`，靠用户**显式新建那块表**才隔离。万一忘了声明：搬家必有的数据空档（staleness）+ delta 护栏（§3.3）保证**不会产出垃圾成本**，只是新数据暂混在旧表 epoch、累计未归零；**事后补声明 + 追溯 `recompute_range`** 即可纠正。
+
+### 3.2 数据模型（新增 1 张表 + 1 列）
+
+`meter` 表（`app/models/energy.py`，单库 app 链）：
+
+| 列 | 类型 | 说明 |
+| --- | --- | --- |
+| `id` | int PK | 内置自增 ID |
+| `label` | str | 人读标签，编址/标识（如 "旧 2G 表 @ Dorpsstraat 1"） |
+| `commodity` | str | 默认 `"electricity"`；预留 `gas`/`heating` |
+| `started_at` | datetime(UTC) | 安装/继承/搬家起点（可在过去） |
+| `ended_at` | datetime(UTC) \| null | null = 当前 active |
+| `reason` | str | `initial` / `meter_swap` / `home_move` / `other` |
+| `note` | str \| null | 备注 |
+| `created_at` | datetime(UTC) | |
+
+`energy_cost_period` 新增 `meter_id`（nullable FK → `meter.id`）：记录该周期归属哪块表，便于审计/按表查询/归档。
+
+### 3.3 计费引擎改造（`energy_cost.py` / `strategies.py` 调用处）
+
+1. `register_at(session, boundary, meter)`：**仅在该 meter 窗口内**取读数（`started_at ≤ recorded_at < ended_at` 且 `≤ boundary` 且过 staleness 护栏）。绝不把旧表读数拉进新表周期。
+2. `compute_period(session, t0)`：
+   - 查 `m0 = meter_at(t0)`、`m1 = meter_at(t1)`。
+   - `m0 is None`（无表覆盖）→ **降级**（不计费）。
+   - `m0.id != m1.id`（周期跨表边界）→ **降级**（D5：丢这一个周期可接受）。
+   - 否则在 `m0` 窗口内 `register_at` 两端、算 delta、计价；新增写 `period.meter_id = m0.id`。
+3. **delta sanity 护栏（D6）**：算出 delta 后，若 `d1/d2/r1/r2` 任一 `< 0`，或任一 `> _MAX_DELTA_KWH`（常量，给一个远超住宅的宽松上限，如每 15 分钟 100 kWh）→ **降级**（兜底表重置/DSMR 回绕/数据毛刺，与换表无关也防住）。
+4. `compute_closed_periods` / `recompute_range`：逐周期按 `meter_at` 判定，无需额外结构。
+
+### 3.4 累计语义（per-meter 归零，D2）
+
+- `expose.py` 累计 `import_cost_total`/`export_revenue_total` 锚点改为**当前 active electricity 表的起点**：`anchor = active electricity meter.started_at`（窗口内首条读数自然 ≥ 它）。换表后累计**从零起一段新序列**，不维护偏移、不跨表累加。
+- `*_today` 日归零实体不变（其本地今天窗口必落在当前表内）。
+- （可选，非核心）暴露"当前电表 label"作为一个文本 sensor，便于 HA 侧识别当前表。
+- **已知行为（可接受）**：累计 `_total` 是 `state_class: total`，换表归零时其值会下台阶，HA 长期统计可能在换表那一刻记一次性负 blip。HA 侧自己存旧值做 down-sample——已与用户确认**先这样、观察后按需处理**（`last_reset` 信号见 §9 杠杆，本里程碑不做）。
+
+### 3.5 API（`app/api/routes/api/` + schemas）
+
+- `GET    /api/energy/meters` — 列出全部表（时间线，active 在前/或按 started_at）。
+- `POST   /api/energy/meters` — 声明换表/继承：`{label, started_at, reason, note?}`；服务层关闭当前 active 同 commodity 表（`ended_at=started_at`）+ 建新表。`started_at` 必须 `≥` 当前 active 表的 `started_at`（拒绝倒挂，仿合同版本"strictly after"）。
+- `PATCH  /api/energy/meters/{id}` — 改 `label`/`note`，或修正 `started_at`（追溯）。
+- `POST   /api/energy/meters/{id}/recompute`（或复用现有 recompute）— 追溯变更后对受影响窗口 `recompute_range`，重判跨表周期与归属。
+- 改了路由/schema → 重导出 OpenAPI 并提交。
+
+### 3.6 前端（并入 Energy 视图）
+
+- 一个"电表（Meters）"管理区：表的时间线（label / 区间 / active 标记 / reason），"我换了表 / 继承了新表"表单（只填 label + 日期 + reason），编辑 label/日期。
+- 追溯保存后给出"已重算受影响周期"的反馈（或提供 recompute 按钮）。
+- 前端闸门见 §8 引用。
+
+### 3.7 迁移与回填（数据安全 runbook）
+
+- Alembic（`alembic_app/`）：建 `meter` 表 + 给 `energy_cost_period` 加 `meter_id` 列（nullable）。
+- **回填（只增不删、幂等、对账）**：
+  1. 若库内已有任何 `dsmr_reading`/`energy_cost_period`，创建一条**初始表** `meter(label="Initial meter", commodity="electricity", started_at = 最早 dsmr_reading.recorded_at（无则最早 period_start，再无则迁移时刻）, ended_at=NULL, reason="initial")`。
+  2. 把现有 `energy_cost_period.meter_id` 全部回填为这条初始表的 id。
+  3. **对账**：回填后 `meter_id IS NULL` 的非降级周期数必须为 0；对不上立即中止、非零退出。
+- **红线**：迁移**不删除/不覆盖**任何 `dsmr_reading`/`energy_cost_period`/旧 `.db`/备份；纯新增表+列+回填。先在备份副本演练再对真实库执行。
+
+## 4. 已锁定决策（讨论后拍板）
+
+- **D1 粒度**：Meter 为一等公民，**不绑定 home**；`label` 编址 + `commodity` 区分品类（每 commodity 一个 active）。
+- **D2 累计**：换表后累计量**归零**（锚当前表起点），直接吃 DSMR 累计 delta，不维护偏移。
+- **D3 合同耦合**：**不引入 home 实体**。合同与电表是两条独立时间线，合同不引用电表 → 同址换表时合同自动照常套用，无需上层抽象。搬家若换合同：用"给现有合同加 version"保持历史连续（多合同时间线积分留作后续杠杆）。
+- **D4 追溯**：`started_at` 可在过去；有效计费起点 = `max(started_at, 数据起点)`；追溯变更触发 `recompute_range`。
+- **D5 边界周期**：跨表周期判 **degraded**（可接受，换表常伴随长时间无数据）。
+- **D6 delta 护栏**：加（负/异常大 delta → degraded），通用兜底。
+- **D7 扩展性**：gas/heating **计费**不在 scope；`commodity` 字段 + 每品类 active 表使未来加表低成本。
+
+## 5. 任务依赖图
+
+```
+M7-T01 (meter 表+模型+列+迁移回填)
+   ├──► M7-T02 (meter 服务层: swap/close/edit, meter_at, 互斥/校验)
+   │       ├──► M7-T03 (计费引擎 meter-aware + delta 护栏 + period.meter_id)
+   │       │        └──► M7-T04 (累计 per-meter 归零, expose 锚点)
+   │       └──► M7-T05 (meter API + 追溯 recompute + OpenAPI)
+   │                └──► M7-T06 (前端电表管理 UI)
+   └──────────────────────────────► M7-T07 (文档/roadmap/收尾)
+```
+
+## 6. 原子任务（任务卡）
+
+### M7-T01 — `meter` 表 + 模型 + `energy_cost_period.meter_id` + 迁移回填 `[schema]`
+
+- **Status**: `done`
+- **Depends**: none
+- **Context**: 引入 Meter 实体的数据地基；为现有数据回填初始表。
+
+**Files**
+- `modify app/models/energy.py`（新增 `Meter`；`EnergyCostPeriod` 加 `meter_id`）
+- `create alembic_app/versions/<rev>_meter_table.py`
+- `modify tests/test_energy_models.py`
+
+**Steps**
+1. 加 `Meter` 模型（字段见 §3.2）；`EnergyCostPeriod` 加 nullable `meter_id` FK。
+2. 写迁移：建表 + 加列；按 §3.7 回填初始表并回填 `meter_id`；带对账（不一致则 raise）。
+3. 测试：模型字段、active-per-commodity 约束的服务层留给 T02；这里测建表/列/回填幂等。
+
+**Out of scope / 不要碰**：计费引擎、expose、API（后续任务）。
+
+**Acceptance criteria**
+- [ ] `meter` 表与 `energy_cost_period.meter_id` 建出；迁移可升降级。
+- [ ] 有历史数据时回填出恰好一条 `reason="initial"` 的 active 表，且非降级周期 `meter_id` 全部非空。
+- [ ] 迁移**不删除/覆盖**任何既有数据；回填幂等。
+- [ ] 校验闸门全绿。
+
+**Reviewer checklist**：回填对账逻辑；空库/有数据两种路径；数据安全红线（无删/覆盖）。
+
+### M7-T02 — Meter 服务层（swap/close/edit + `meter_at` + 互斥/校验）
+
+- **Status**: `done`
+- **Depends**: M7-T01
+- **Context**: 换表/继承的业务逻辑与按时刻查表。
+
+**Files**
+- `create app/services/meters.py`
+- `create tests/test_meters.py`
+
+**Steps**
+1. `meter_at(session, ts, commodity="electricity")`（半开区间）。
+2. `declare_meter(session, *, label, started_at, reason, commodity="electricity", note=None)`：校验 `started_at ≥ 当前 active 同 commodity 表的 started_at`（拒绝倒挂）；关闭旧 active（`ended_at=started_at`）+ 建新 active。
+3. `list_meters` / `update_meter`（label/note/started_at）；改 started_at 时维持区间自洽。
+4. 测试：互斥（每 commodity 单 active）、倒挂拒绝、追溯、`meter_at` 边界。
+
+**Out of scope**：API、引擎、前端。
+
+**Acceptance criteria**
+- [ ] 每 commodity 至多一个 active；swap 正确续接区间。
+- [ ] `meter_at` 半开区间正确（含边界）。
+- [ ] 校验闸门全绿。
+
+**Reviewer checklist**：互斥与续接的事务正确性；追溯改 started_at 的区间一致性。
+
+### M7-T03 — 计费引擎 meter-aware + delta 护栏 + `period.meter_id`
+
+- **Status**: `done`
+- **Depends**: M7-T02
+- **Context**: 让计费永不跨表算 delta，并兜底异常 delta。
+
+**Files**
+- `modify app/services/energy_cost.py`
+- `modify tests/test_energy_cost.py`
+
+**Steps**
+1. `register_at` 限定在传入 meter 的窗口内取读数。
+2. `compute_period`：按 §3.3 判定 `m0/m1`；无表/跨表 → 降级；否则算 delta、写 `meter_id`。
+3. 加 `_MAX_DELTA_KWH` 常量与护栏：任一寄存器 delta `<0` 或 `>上限` → 降级。
+4. `compute_closed_periods`/`recompute_range` 逐周期 meter 判定。
+5. 测试：同表内正确；跨表周期降级；负/超大 delta 降级；无 active 表降级。
+
+**Out of scope**：expose 锚点（T04）、API（T05）。
+
+**Acceptance criteria**
+- [ ] 跨 meter 边界周期 = degraded；无表覆盖 = degraded。
+- [ ] 负 delta / 超 `_MAX_DELTA_KWH` = degraded，绝不产负/巨额成本。
+- [ ] 同表内 delta 计费与归属 `meter_id` 正确。
+- [ ] 校验闸门全绿。
+
+**Reviewer checklist**：staleness × meter 窗口的交互；护栏阈值是否远超住宅、不会误伤真实用量；recompute 重判归属。
+
+### M7-T04 — 累计 per-meter 归零（expose 锚点）
+
+- **Status**: `done`
+- **Depends**: M7-T03
+- **Context**: 换表后 MQTT 累计量从零起算。
+
+**Files**
+- `modify app/integrations/expose.py`
+- `modify tests/test_energy_expose.py`
+
+**Steps**
+1. 累计 `import_cost_total`/`export_revenue_total` 锚点改为**当前 active electricity 表的 `started_at`**（替换 FU11 的 `max(合同, 首周期)`）。
+2. `*_today` 不变；确认无非降级周期/无 active 表时仍 `None` 保护。
+3.（可选）暴露当前电表 label 文本实体。
+4. 测试：换表后累计仅含当前表；anchor 取当前表起点。
+
+**Out of scope**：API/前端。
+
+**Acceptance criteria**
+- [ ] 累计量锚 = 当前 active electricity meter 起点；换表归零。
+- [ ] None 保护分支保留；daily 实体不受影响。
+- [ ] 校验闸门全绿。
+
+**Reviewer checklist**：与 FU11 行为差异是否符合 D2；无表/空数据分支。
+
+### M7-T05 — Meter API + 追溯 recompute + OpenAPI
+
+- **Status**: `done`
+- **Depends**: M7-T02
+- **Context**: 暴露电表 CRUD 与换表声明；追溯后重算。
+
+**Files**
+- `create app/api/routes/api/meters.py`
+- `create app/schemas/meter.py`
+- `modify app/api/routes/...`（注册路由）
+- `modify openapi/openapi.json`, `openapi/openapi.yaml`
+- `create tests/test_api_meters.py`
+
+**Steps**
+1. `GET/POST/PATCH /api/energy/meters`（+ 追溯触发 `recompute_range`）。
+2. 鉴权沿用 `require_session`。
+3. `python scripts/export_openapi.py` 并提交 `openapi/`。
+4. 测试：列出/声明换表/编辑/倒挂拒绝/追溯重算。
+
+**Out of scope**：前端。
+
+**Acceptance criteria**
+- [ ] 端点行为符合 §3.5；追溯变更触发受影响窗口重算。
+- [ ] `git diff --exit-code openapi/` 干净（已重导出提交）。
+- [ ] 校验闸门全绿。
+
+**Reviewer checklist**：错误码（倒挂/不存在）；recompute 范围是否覆盖受影响周期。
+
+### M7-T06 — 前端电表管理 UI
+
+- **Status**: `done`
+- **Depends**: M7-T05
+- **Context**: 让用户在 Energy 页声明换表、查看电表时间线。
+
+**Files**
+- `create frontend/src/energy/MeterManager.tsx`
+- `modify frontend/src/energy/EnergyPage.tsx`, `frontend/src/energy/hooks.ts`
+- `modify frontend/src/energy/*.test.tsx`
+- `modify frontend/src/api/schema.d.ts`（`npm run codegen`）
+
+**Steps**
+1. `npm run codegen` 拉新端点类型。
+2. 电表时间线 + "换表/继承"表单（label + 日期 + reason）+ 编辑。
+3. 追溯保存后反馈"已重算"。
+4. 前端闸门（§8）。
+
+**Out of scope**：后端。
+
+**Acceptance criteria**
+- [ ] 能列出/声明换表/编辑；UI 合理。
+- [ ] 前端 lint/typecheck/test/build 全绿；`schema.d.ts` 已 codegen。
+
+**Reviewer checklist**：日期→后端时区语义（沿用 FU10 本地午夜 naive 约定）；空状态/加载/错误。
+
+### M7-T07 — 文档 / OpenAPI / roadmap 收尾
+
+- **Status**: `done`
+- **Depends**: M7-T01..T06
+- **Context**: 把 M7 落档、更新 roadmap 与索引。
+
+**Files**
+- `modify docs/roadmap.md`（新增 M7 条目，标完成）
+- `modify docs/design/README.md`（索引加 m7）
+- `modify docs/design/m7-meter-epochs-archival.md`（Status 收尾）
+- `modify docs/*`（如新增 meter 模块说明，按需）
+
+**Acceptance criteria**
+- [ ] roadmap/README/本文 Status 一致；OpenAPI 已是最新并提交。
+- [ ] 校验闸门全绿。
+
+## 7. 构建上下文完整性（M1 教训）
+
+- 本里程碑只**新增** `app/services/meters.py`、`app/api/routes/api/meters.py`、`app/schemas/meter.py`、`alembic_app/versions/<rev>_*.py` 与前端文件；均落在现有 `Dockerfile` 的 `COPY app ./app` / `COPY alembic_app ./alembic_app` / 前端构建阶段覆盖范围内，**无新增顶层目录**。
+- `tests/test_deployment.py::test_dockerfile_copy_sources_exist` 应仍绿；删/移文件时按 README 规则 grep 构建清单（本里程碑预期无删除）。
+
+## 8. 前端校验闸门
+
+`frontend/` 下：`npm run lint && npm run typecheck && npm run test && npm run build`；改了端点/schema 还需 `npm run codegen` 并提交 `schema.d.ts`。
+
+## 9. 后续杠杆（本里程碑不做，留痕）
+
+- **Home/Site 分组**：若将来要"一个地址下多品类表合并出账 + 整屋归档"，再加薄分组层（可仅 `site_label` 字段，不必新实体）。
+- **多合同时间线积分**：让 `summarize` 跨多个非重叠合同积分固定费/抵扣，免去搬家"加 version"的折中。
+- **换表时给累计实体发 `last_reset` 信号**：消除 HA 长期统计在归零时刻的一次性负 blip（需给 expose/discovery 加 `last_reset` 管线，FU11 当时为省事未做）。已与用户确认本里程碑**先不做**，先观察、需要时再加。
+- **Gas / 区域供暖计费**：`commodity!="electricity"` 的 strategy 与寄存器映射。
+- **当前电表 label 暴露给 HA**、按表/按地址的成本报表分段。
+
+## 10. 里程碑完成定义（DoD）
+
+✅ **已完成**（M7-T01..T07 全部 done）
+
+- `meter` 数据地基 + 回填上线；计费引擎永不跨表算 delta，跨表/无表/异常 delta 一律降级。
+- 累计量按当前表归零；追溯换表可重算。
+- Meter CRUD API + 前端管理 UI 可用；OpenAPI/schema 已同步。
+- 全程数据安全红线无违反；pytest/ruff/前端闸门全绿。
+- 人工 walkthrough：声明一次（含追溯）换表 → 旧表周期保留、跨表周期降级、新表从零累计、HA 累计实体不出现负/巨额跳变。
@@ -0,0 +1,114 @@
+# Meter Epochs（电表生命周期 / 换表归档）
+
+本文档说明 **Meter epoch** 概念、换表声明流程、计费隔离行为、累计量归零、追溯重算，以及与 HA 累计 blip 的已知行为。
+
+## 为什么需要 Meter epoch
+
+计费引擎采用**寄存器差值（delta）模型**：每 15 分钟成本 =（周期末读数 − 周期初读数）× 单价。荷兰 2G 智能电表退网后，电网公司会把表换成 4G 表（同址换表）；搬家继承新表也是同类场景。
+
+问题在于：**新表的寄存器基数与旧表无关**，若跨表算 delta，会产出负成本或巨额假成本。Meter epoch 让引擎知道"某时刻起属于哪一块物理表"，从而永不跨表算 delta。
+
+## 核心概念
+
+一条 `meter` 记录 = **一块物理电表的一段安装期** `[started_at, ended_at)`：
+
+- `started_at`：表安装/继承/搬家的起点（可在过去，追溯声明）。
+- `ended_at`：null = 当前 active；非 null = 已退役表的结束时刻。
+- `label`：人读标签，便于识别（如 "旧 2G 表 @ Dorpsstraat 1"）。
+- `reason`：`initial`（初始建档）/ `meter_swap`（换表）/ `home_move`（搬家）/ `other`。
+- `commodity`：默认 `electricity`；为未来 gas/heating 预留，每 commodity 至多一个 active 表。
+
+**换表** = 关闭旧 active 表（`ended_at = T`）+ 新建 `started_at = T` 的表。系统**无法自动识别换表**（DSMR 帧无电表序列号），靠用户**显式声明**才能隔离。
+
+## 计费隔离行为
+
+每个 15 分钟计费周期，引擎先查该周期两端（t0/t1）分别属于哪块表：
+
+| 情况 | 结果 |
+| --- | --- |
+| 同一块表（正常）| 在表窗口内取读数、算 delta、正常计费 |
+| 无表覆盖（未声明）| **降级**（成本置 0，`degraded=true`） |
+| 跨表边界（t0 ≠ t1 的表）| **降级**（丢这一个周期，可接受；换表常伴随长时间无数据） |
+| delta < 0 或 > 100 kWh/15min | **降级**（兜底异常，如 DSMR 回绕/毛刺，与换表无关也防住） |
+
+**忘了声明换表怎么办**：搬家必有的数据空档（staleness）+ delta 护栏保证不会产出垃圾成本，只是新数据暂混在旧表 epoch、累计未归零。事后补声明 + 追溯重算即可纠正（见下方"追溯换表"）。
+
+## 换表声明流程
+
+### 通过前端（Energy 页 → Meters tab）
+
+1. 在 Energy 页切到 **Meters** tab，查看当前电表时间线。
+2. 点击"声明换表 / 继承新表"，填写：
+   - **Label**：新表的人读标签（如 "4G 新表 2026"）
+   - **安装日期**：新表的 `started_at`（可选择历史日期追溯）
+   - **Reason**：`meter_swap` / `home_move` / `other`
+3. 保存后，旧表自动关闭（`ended_at = 填写日期`），新表成为 active。
+4. 如填写的是过去日期，系统自动触发受影响窗口的重算（`recompute_range`），跨表周期变为降级，新表内周期重新归属。
+
+### 通过 API
+
+```http
+POST /api/energy/meters
+Content-Type: application/json
+
+{
+  "label": "4G 新表 2026",
+  "started_at": "2026-07-01T00:00:00",
+  "reason": "meter_swap",
+  "note": "荷兰电网公司换装"
+}
+```
+
+`started_at` 必须 `≥` 当前 active 表的 `started_at`（拒绝倒挂）。
+
+查询所有表（时间线）：
+
+```http
+GET /api/energy/meters
+```
+
+编辑 label / 备注 / 修正日期：
+
+```http
+PATCH /api/energy/meters/{id}
+```
+
+## 追溯换表（started_at 在过去）
+
+若换表日期在过去但当时忘了声明：
+
+1. 声明新表，填写过去的安装日期。
+2. 系统自动对 `[started_at, now]` 范围内的周期触发 `recompute_range`：
+   - 跨表边界周期 → 降级。
+   - 归属新表窗口内的周期 → `meter_id` 更新为新表。
+3. MQTT 累计量锚点切换至新表起点，下一次 expose 推送时累计量从新表起点重算。
+
+## 累计量归零（per-meter）
+
+MQTT 上报的累计成本实体（`import_cost_total` / `export_revenue_total`）锚点 = **当前 active electricity 表的 `started_at`**。换表后：
+
+- 累计量从新表安装时刻起重新累加，不跨表维护历史偏移。
+- 日归零实体（`*_today`）不受影响（其窗口必落在当前表内）。
+
+### 已知行为：HA 长期统计的一次性负 blip
+
+累计实体 `state_class: total`，换表归零时其值会**下台阶**。Home Assistant 长期统计（energy dashboard / statistics）可能在换表那一刻记录一次性负 blip。
+
+这是**已知、可接受的行为**：HA 自身存旧值做 down-sample，短期 blip 不影响日常电费读数。已与用户确认先这样观察。如需消除 blip，可在未来通过 `last_reset` 信号通知 HA（见设计文档 §9 后续杠杆，本里程碑不做）。
+
+## 回填（迁移时的初始表）
+
+首次升级到含 M7 迁移的版本时：
+
+- 若库内已有任何 `dsmr_reading` / `energy_cost_period`，迁移自动创建一条 `reason="initial"` 的初始表（`started_at = 最早 dsmr_reading.recorded_at`），并回填现有 `energy_cost_period.meter_id`。
+- 若是全新空库，初始表不创建（无历史数据）。
+- 回填幂等：重复跑迁移不会创建多条初始表；回填后对账（非降级周期 `meter_id IS NULL` 数必须为 0）。
+
+## 非目标（本里程碑不做）
+
+- Gas / 区域供暖的计费（`commodity != "electricity"` 的 strategy）。
+- "家庭（home）"分组实体；多合同时间线积分。
+- 自动识别换表（DSMR 帧无电表序列号，无法自动识别，靠用户显式声明）。
+- `last_reset` 信号（消除 HA 长期统计 blip）。
+
+> 详细设计与任务卡：[`docs/design/m7-meter-epochs-archival.md`](./design/m7-meter-epochs-archival.md)
@@ -0,0 +1,134 @@
+# SDM120 Modbus 协议（从官方 PDF 提取）
+
+> 来源：`docs/references/SDM120-MODBUS_Protocol.pdf`
+> （Eastron SDM120 Modbus Smart Meter Modbus Protocol Implementation **V2.4**）
+> 本文件是 PDF 的可读化提取，供本项目的 Modbus 采集驱动设计参考。**以官方 PDF 为准**，本文件如有出入以 PDF 为准。
+
+## 0. 本项目的接入方式（重要）
+
+SDM120 物理层是 **Modbus RTU（RS-485 串口）**。本项目通过一个 **Modbus-TCP 网关**接入：
+
+- 后端用 **Modbus TCP**（`IP:port`）连到网关，网关在串口侧转成 RTU 与电表通信。
+- TCP 帧用 MBAP header、**无 CRC**（CRC/Error Check 由网关在 RTU 侧处理）。本文档里 RTU 帧的 `Error Check (Lo/Hi)` 字段在 TCP 模式下不需要我们关心。
+- **Slave Address / Unit ID = 电表的 Meter ID**（默认 `1`，范围 1–247），在 TCP 请求里作为 unit id 传入。
+- 若以后直连串口（RTU），才需要管波特率 / 校验位 / CRC（见 §5 holding 寄存器）。
+
+## 1. 协议帧格式
+
+MODBUS 定义 master 查询 / slave 响应的格式。Eastron 电表用 16-bit 寄存器在主从间传值，**但实际数据是 32-bit IEEE-754 浮点**，因此每个测量参数占**两个相邻的 16-bit 寄存器**。
+
+### Query（master → slave，RTU 帧）
+
+| 字段 | 说明 |
+| --- | --- |
+| Slave Address | 8-bit，目标从机地址 1–247（0=广播，Eastron 不支持广播） |
+| Function Code | 8-bit，功能码（Eastron 支持 **03 / 04 / 08 / 16(=0x10)**） |
+| Start Address (Hi/Lo) | 16-bit 起始寄存器地址；**寄存器成对使用、从 0 开始，所以起始地址必须是偶数** |
+| Number of Points (Hi/Lo) | 16-bit 请求的寄存器数量；**也必须是偶数**（成对读浮点） |
+| Error Check (Lo/Hi) | 16-bit CRC（RTU 模式；TCP 网关模式无此字段） |
+
+### Response（slave → master）
+
+| 字段 | 说明 |
+| --- | --- |
+| Slave Address | 响应从机地址 |
+| Function Code | 与查询相同的功能码（表示识别并已响应） |
+| Byte Count | 8-bit，本次返回的数据字节数 |
+| Data (寄存器对) | 每个寄存器 Hi byte / Lo byte，按"高寄存器在前"排列 |
+| Error Check (Lo/Hi) | 16-bit CRC（RTU 模式） |
+
+### Exception Response（异常响应）
+
+- 异常响应的 Function Code = 查询功能码 **OR 0x80**（最高位置 1）。
+- 数据是单字节 Error Code（异常码）。
+- PDF 正文写了"见后文 Table Of Exception Codes"，但提取的 8 页里**没有附上该表**。标准 Modbus 异常码（供参考，非本 PDF 内容）：`01` 非法功能、`02` 非法数据地址、`03` 非法数据值、`04` 从机设备故障。
+
+## 2. 功能码
+
+| 功能码 | 作用 | 寄存器区 |
+| --- | --- | --- |
+| **04** | Read Input Registers（读输入寄存器，3X）—— **所有测量值都在这里** | 30001+ |
+| **03** | Read Holding Registers（读保持寄存器，4X）—— 配置项 | 40001+ |
+| **16 / 0x10** | Write Holding Registers（写保持寄存器，4X）—— 改配置 | 40001+ |
+| 08 | Diagnostics（诊断） | — |
+
+> ⚠️ **测量值用 FC 04（输入寄存器），不是 FC 03。** 这是最常见的踩坑点。
+
+## 3. 浮点数据编码
+
+- 每个参数 = **32-bit IEEE-754 float**，占两个相邻 16-bit 寄存器。
+- **字序（word order）= 大端：高寄存器在前。**
+- **字节序（byte order）= 大端：寄存器内高字节在前。**
+- 即整体就是标准大端 float（`>f`），4 字节顺序 = `[Reg1 Hi][Reg1 Lo][Reg2 Hi][Reg2 Lo]`。
+
+**实例（来自 PDF）**
+
+| 含义 | 原始 4 字节 (hex) | 解码值 |
+| --- | --- | --- |
+| Volts 1 | `43 66 33 34` | `230.2` V |
+| Demand Time | `3F 80 00 00` | `1.0` |
+| Network Node | `42 70 00 00` | `60.0` |
+
+> Python 解码：`struct.unpack('>f', bytes([0x43,0x66,0x33,0x34]))[0]` → `230.2`。
+> pymodbus 用 `BinaryPayloadDecoder.fromRegisters(regs, byteorder=Endian.BIG, wordorder=Endian.BIG)`。
+
+## 4. 输入寄存器表（FC 04 读测量值）
+
+全部为 `Float`，长度 4 字节，每项占 2 个寄存器。"Hex 起始"是 Modbus 协议起始地址（即 Start Address Hi/Lo）。
+
+| 寄存器 | 参数 | 单位 | Hex 起始 |
+| --- | --- | --- | --- |
+| 30001 | Voltage（电压） | Volts | `0000` |
+| 30007 | Current（电流） | Amps | `0006` |
+| 30013 | Active power（有功功率） | Watts | `000C` |
+| 30019 | Apparent power（视在功率） | VA | `0012` |
+| 30025 | Reactive power（无功功率） | VAr | `0018` |
+| 30031 | Power factor（功率因数） | — | `001E` |
+| 30071 | Frequency（频率） | Hz | `0046` |
+| 30073 | Import active energy（导入有功电能） | kWh | `0048` |
+| 30075 | Export active energy（导出有功电能） | kWh | `004A` |
+| 30077 | Import reactive energy（导入无功电能） | kvarh | `004C` |
+| 30079 | Export reactive energy（导出无功电能） | kvarh | `004E` |
+| 30085 | Total system power demand | W | `0054` |
+| 30087 | Maximum total system power demand | W | `0056` |
+| 30089 | Import system power demand | W | `0058` |
+| 30091 | Maximum import system power demand | W | `005A` |
+| 30093 | Export system power demand | W | `005C` |
+| 30095 | Maximum export system power demand | W | `005E` |
+| 30259 | Current demand | Amps | `0102` |
+| 30265 | Maximum current demand | Amps | `0108` |
+| 30343 | Total active energy（总有功电能） | kWh | `0156` |
+| 30345 | Total reactive energy（总无功电能） | kvarh | `0158` |
+
+**读取分块建议**：`0x0000–0x005E`（30001–30095）地址连续，可一次块读；`0x0102/0x0108`、`0x0156/0x0158` 各为独立小块。整表用 2–3 次块读即可覆盖，减少 Modbus 事务数。
+
+### 常用核心子集（日常监控够用）
+
+电压 `0000`、电流 `0006`、有功功率 `000C`、功率因数 `001E`、频率 `0046`、导入有功电能 `0048`、导出有功电能 `004A`、总有功电能 `0156`。
+
+## 5. 保持寄存器表（FC 03 读 / FC 16 写配置）
+
+| 寄存器 | 参数 | Hex 起始 | 格式 | 说明 |
+| --- | --- | --- | --- | --- |
+| 40013 | Relay Pulse Width | `000C` | Float | 继电器脉宽 60/100/200 ms，默认 100ms |
+| 40019 | Network Parity Stop | `0012` | Float | 0=1停止位无校验(默认)，1=1停止位偶校验，2=1停止位奇校验，3=2停止位无校验；**改后需重启生效** |
+| 40021 | Meter ID | `0014` | Float | 从机地址 1–247，默认 1 |
+| 40029 | Baud rate | `001C` | Float | 0=2400(默认)，1=4800，2=9600，5=1200 |
+| 40087 | Pulse 1 output mode | `0056` | Float | 0001 导入有功，0002 导入+导出有功，0004 导出有功(默认)，0005 导入无功，0006 导入+导出无功，0008 导出无功 |
+| 463745 | Time of scroll display | `F900` | HEX 2字节 | 滚动显示时间 0–30s，默认 0（不滚动） |
+| 463761 | Pulse 1 output | `F910` | HEX 2字节 | 0000:0.001kWh/imp(默认)，0001:0.01，0002:0.1，0003:1 kWh/imp |
+| 463777 | Measurement mode | `F920` | HEX 2字节 | 1:total=import，2:total=import+export(默认)，3:total=import-export |
+| 464513 | Serial number | `FC00` | uint32 4字节 | 序列号，**只读** |
+| 464515 | Meter code | `FC02` | Hex 2字节 | 设备码=`0020`，**只读** |
+| 464516 | Software version | `FC03` | Hex 2字节 | 软件版本，**只读** |
+
+> ⚠️ 写保持寄存器（改 Meter ID / 波特率 / 校验位等）会改变电表通信参数，配错可能导致**通信中断**。本项目默认**只读采集**，不建议在自动化链路里写电表配置。
+
+## 6. 给本项目采集驱动的要点小结
+
+1. 走 **Modbus TCP 网关**：`ModbusTcpClient(host, port)`，`slave=<Meter ID>`。
+2. 测量值用 **FC 04 / 输入寄存器**，按 §4 地址读。
+3. 解码 **大端 float32**（word & byte 都大端，高寄存器在前）。
+4. 起始地址与数量**都用偶数**（成对读）。
+5. 默认**只读**，不写电表配置寄存器。
+6. 不同型号电表 → 不同"寄存器 profile"。本表是 `sdm120` 这一个 profile 的定义。
@@ -0,0 +1,249 @@
+# Tibber API + 荷兰电价 + DSMR Reader 参考
+
+> 本文件汇总 M6（动态/固定电价 → 实时买卖电费计算）所需的全部外部事实，供 `docs/design/m6-tibber-dynamic-energy.md` 与实现者直接 refer。
+> 来源：Tibber GraphQL introspection（实证）、Tibber Explorer demo 数据、Tibber NL support 文档、用户实际合同与 DSMR Reader 配置（2026-06 整理）。
+> 凡标「✅ 实证」的为代码/数据验证过的事实；金额类以用户真实账单 / 合同生效后真实 token 为最终准（见末尾「待真实数据核对」）。
+
+---
+
+## 1. Tibber GraphQL API
+
+- **Endpoint**：`POST https://api.tibber.com/v1-beta/gql`
+- **认证**：HTTP header `Authorization: Bearer <token>`；token 在 [developer.tibber.com](https://developer.tibber.com) 登录后生成（每个 Tibber 账户一个）。
+- **在线 Explorer**：[developer.tibber.com/explorer](https://developer.tibber.com/explorer)，自带一个公共 **demo token**。
+  - ⚠️ **demo token 现在只能做 schema introspection 与历史 demo 数据查询**；对 `viewer` 的真实数据查询返回 `UNAUTHENTICATED`。要拿自己家的实时价，必须用**自己账户的 token**。
+
+### 1.1 `Price` 类型（✅ introspection 实证）
+
+`Price` 对象恰好 6 个字段：
+
+| 字段 | 类型 | 含义 |
+| --- | --- | --- |
+| `total` | Float | **全包价 = energy + tax**（即 App 里的 All-in Price，含 spot+能源税+VAT 等）|
+| `energy` | Float | 纯能源/现货分量（ex-VAT 市场价）|
+| `tax` | Float | 税费分量（能源税 + VAT 合并）|
+| `startsAt` | String | 该价格段起点（ISO8601，**含时区偏移**，如 `+02:00`）|
+| `currency` | String! | 币种（唯一 non-null 字段；NL 为 EUR，demo 为 SEK）|
+| `level` | PriceLevel | 价格档枚举（`VERY_CHEAP/CHEAP/NORMAL/EXPENSIVE/VERY_EXPENSIVE`）|
+
+**✅ 实证**：`total == energy + tax` 精确成立（见 §1.4 样本）。
+
+### 1.2 15 分钟价格：`Subscription.priceInfoRange`（✅ introspection 实证）
+
+- **字段**：`currentSubscription.priceInfoRange`
+- **参数**：`resolution: PriceInfoRangeResolution!`（必填）、`first: Int`、`last: Int`、`before: String`、`after: String`（游标分页）
+- **resolution 枚举 `PriceInfoRangeResolution`**：值 `DAILY` / `HOURLY` / `QUARTER_HOURLY`
+  - ⚠️ 注意别用错枚举：另有 `PriceResolution`（只有 HOURLY/DAILY，**无 QUARTER_HOURLY**）和 `PriceInfoResolution`——`priceInfoRange` 用的是 **`PriceInfoRangeResolution`**。
+- **返回**：`SubscriptionPriceConnection { nodes: [Price]!, edges: [...], pageInfo }`
+- **废弃说明**：老的 `priceInfo.range`（`deprecationReason: "use Subscription.priceInfoRange instead"`）**不支持 QUARTER_HOURLY**，必须改用 `Subscription.priceInfoRange`。
+- **✅ 实证（demo key，2018 历史日）**：`QUARTER_HOURLY` 返回 **96 个节点、间隔精确 15 分钟**；无真 15 分钟价的历史日，API 把**小时价重复成 4 个相同刻钟**（00/15/30/45 同值，到下一整点才变）；NL 当前数据则是真 15 分钟。
+- **解析注意**：**不要假设固定 96 个节点 / 固定 15 分钟间隔**，按 `startsAt` 逐点存最稳。
+
+**15 分钟查询（拉今天 96 个刻钟）**：
+```graphql
+{ viewer { homes { id currentSubscription {
+    priceInfoRange(resolution: QUARTER_HOURLY, first: 96) {
+      nodes { startsAt total energy tax currency level }
+} } } } }
+```
+
+### 1.3 小时价 / 当前价 / 探测：`priceInfo`
+
+`currentSubscription.priceInfo` 含 `current`（当前价）、`today[]`、`tomorrow[]`（次日价约 13:00 CET 发布）。探测账户能力 + 当前价：
+```graphql
+{ viewer { homes {
+    id appNickname
+    features { realTimeConsumptionEnabled }
+    currentSubscription { priceInfo {
+      current  { total energy tax startsAt level currency }
+      today    { total energy tax startsAt level }
+      tomorrow { total energy tax startsAt level }
+} } } } }
+```
+
+### 1.4 现成 curl + 样本响应
+
+```bash
+# 15 分钟价（换成自己账户 token；demo token 拿不到 viewer 真实数据）
+curl -s -X POST https://api.tibber.com/v1-beta/gql \
+  -H "Authorization: Bearer <YOUR_TOKEN>" -H "Content-Type: application/json" \
+  -d '{"query":"{ viewer { homes { id currentSubscription { priceInfoRange(resolution: QUARTER_HOURLY, first: 96) { nodes { startsAt total energy tax currency } } } } } }"}'
+```
+
+**样本：`priceInfo`（demo，瑞典家庭，SEK）**
+```json
+{"current": {"total": 0.8239, "energy": 0.5663, "tax": 0.2576,
+             "startsAt": "2026-06-23T14:00:00.000+02:00", "level": "NORMAL", "currency": "SEK"},
+ "today":   [{"total": 1.276, "energy": 0.928, "tax": 0.348,
+              "startsAt": "2026-06-23T00:00:00.000+02:00", "level": "VERY_EXPENSIVE"}, … 24 项],
+ "tomorrow":[… 24 项]}
+```
+
+**样本：`priceInfoRange` QUARTER_HOURLY（demo，2018-11-02，96 节点）**
+```json
+{"nodes": [
+  {"startsAt":"2018-11-02T00:00:00.000+01:00","total":0.63,  "energy":0.435,"tax":0.195,"currency":"SEK"},
+  {"startsAt":"2018-11-02T00:15:00.000+01:00","total":0.63,  "energy":0.435,"tax":0.195,"currency":"SEK"},
+  {"startsAt":"2018-11-02T00:30:00.000+01:00","total":0.63,  "energy":0.435,"tax":0.195,"currency":"SEK"},
+  {"startsAt":"2018-11-02T00:45:00.000+01:00","total":0.63,  "energy":0.435,"tax":0.195,"currency":"SEK"},
+  {"startsAt":"2018-11-02T01:00:00.000+01:00","total":0.6141,"energy":0.4223,"tax":0.1918,"currency":"SEK"},
+  … 共 96 个，末节点 23:45 total 0.6342]}
+```
+（注意 00:00–00:45 四个刻钟同值 = 小时价被重复；`total==energy+tax`。）
+
+---
+
+## 2. 荷兰电价构成（Tibber NL + 用户合同）
+
+> 所有金额**含 VAT（incl. btw）**，除非另注。VAT/BTW 标准税率 **21%**。
+
+| 分量 | 荷兰语 | 单位 | 值 / 说明 |
+| --- | --- | --- | --- |
+| 现货/市场价 | marktprijs / dynamische kwartierprijs | €/kWh | 每 15 分钟跟随交易所；= API `energy` |
+| 买侧采购费 | **inkoopvergoeding** | €/kWh | **€0.0248**（覆盖 onbalans + 绿证；见下「相等」事实）|
+| 卖侧上网费 | **verkoopvergoeding** | €/kWh | **€0.0248**（2026-01-01 起）|
+| 能源税 | energiebelasting | €/kWh（含 VAT）| 2026 第一档（0–10000 kWh）≈ **€0.1108**；2025 ≈ €0.1228；高档更低 |
+| 增值税 | BTW | % | **21%** |
+| 固定月费 | vast bedrag / leveringskosten | €/月/合同 | Tibber **€5.99/月**（电、气各一次）|
+| 电网维护费 | netbeheerkosten / systeembeheerkosten | €/天或/月 | 电网公司定、供应商代收；按地区，2026 约 +3.38% |
+| 能源税抵扣 | heffingskorting / vermindering energiebelasting | €/年/连接 | 政府年度减免，从总费用扣 |
+| ODE | Opslag Duurzame Energie | €/kWh | **现为 0**（已并入 energiebelasting）|
+
+**✅ 关键事实（Tibber NL 文档原文）**：
+> "De verkoopvergoeding van 2,48 cent is gelijk aan de inkoopvergoeding die je bij je afgenomen stroom betaalt."
+> （卖侧 verkoopvergoeding 2.48 分 = 买侧 inkoopvergoeding。）
+
+→ **买卖服务费相等（均 €0.0248/kWh）**，在买卖里一进一出**相互抵消**。
+
+---
+
+## 3. 净计量（saldering）、回送（teruglevering）、负电价、2027
+
+### 3.1 回送价（净计量期内，文档原文）
+> "Op het moment dat je teruglevert geven we je per kWh de beursprijs die op dat moment geldt …, inclusief energiebelasting en inkoopvergoeding plus de btw minus de verkoopvergoeding."
+
+即净计量期内回送价 = `beursprijs + energiebelasting + inkoopvergoeding + btw − verkoopvergoeding`。因 inkoopvergoeding = verkoopvergoeding 抵消 → **= 全额零售价**（spot+能源税+VAT），正是 saldering "回送 1 度 = 用 1 度"的本质。
+
+### 3.2 年末盈余 / 取消净计量后（文档原文，Scenario 2）
+> "Voor de overproductie van 500 kWh heb je recht op de beursprijs en de inkoopvergoeding, maar heb je geen recht op de energiebelasting. … ontvang je nog een factuur van ons voor de te veel uitgekeerde belastingen …"
+
+即**超额回送（或 2027 取消净计量后）**：盈余按 `beursprijs + inkoopvergoeding − verkoopvergoeding`（**无能源税**）计价 → 因两费抵消 → **= 纯 spot**。
+
+### 3.3 净计量机制
+- 法定**按自然年**结算；可抵扣到「用电量」为止（回送抵到用电为止）。
+- Tibber 不用预付，**净计量周期在第 12 张账单后结束**。
+- **2027 起荷兰取消净计量（saldering stopt in 2027）**——用户据此设计：**不再考虑净计量，直接按实时买卖算**。
+
+### 3.4 负电价
+- 负价时**用电**：理论上你拿钱（但仍计能源税，净计量期内税会退回）。
+- 负价时**回送**：你要为回送的电付那个负价（= 倒贴）。
+- 因 Tibber 给的是 all-in `total`（已含能源税），**只有 spot 负到比能源税还多，total 才转负**；中等负价时 total 仍正（照付）。
+- **结论：负电价不需要特殊处理**——`buy=total` 与 `sell=total−能源税` 符号自洽。
+
+---
+
+## 4. 本项目采用的买/卖价公式（M6）
+
+> spot 取 API `energy`；`total = energy + tax`（全包）。**买价直接用 `total`**，卖价从 `total` 扣掉卖电不交的能源税。
+
+- **Tibber 动态合同**（post-2027 口径）：
+  - 买价 `buy = price.total`
+  - 卖价 `sell = price.total − energy_tax_per_kwh − sell_adjust`（`sell_adjust` 默认 0；含 VAT 归己；买卖费抵消已隐含在 total 里）
+- **固定合同（manual，双费率）**：
+  - 买价 `buy_档 = energy_buy_档 + energy_tax`（档 ∈ {normal, dal}）
+  - 卖价 `sell_档 = sell_档`（回送价，**无能源税**）
+- **固定费/抵扣不进每度**：`network_fee`、`management_fee`（月→天）、`heffingskorting`（年→天）在**日/月/年汇总**层加减。
+- 详见 `docs/design/m6-tibber-dynamic-energy.md` §3.4。
+
+---
+
+## 5. 用户当前固定合同（manual 实例，2026-06）
+
+> 双费率（NL：`_1`=dal/低谷、`_2`=normal/高峰）。以下为当前值，会随合同阶段/年度变（系统按"加新版本+生效日期"留底）。
+
+| 项 | 当前值 | 备注 |
+| --- | --- | --- |
+| 能源价 normal（高） | €0.133/kWh | 买侧，含 VAT，不含能源税 |
+| 能源价 dal（低） | €0.127/kWh | 买侧 |
+| 回送价 normal | （现与 dal 同）| 卖侧，分档但现同价；系统仍分开填 |
+| 回送价 dal | — | 卖侧 |
+| 能源税 energiebelasting | 待填（≈€0.1108）| 含 VAT，加到买价 |
+| ODE | 0 | 已并入能源税 |
+| 电网维护费 | 待填 | 按天（合同按天收）|
+| 供应商管理费 | ≈€0.329/天（≈€9.87/月）| 对应 Tibber 的 €5.99/月 |
+| heffingskorting | 待填 | 年度减免，汇总时扣 |
+| 回送阶梯罚金 terugleverkosten | **不做** | 按自然年累计、阶梯式；用户住不到年底算不准，M6 不实现 |
+
+---
+
+## 6. DSMR Reader → MQTT
+
+### 6.1 取数方式
+- 用 **Telegram JSON**（单 topic **`dsmr/json`**，一条 = 一帧完整 telegram 的 JSON），**不用** split-topic（每字段一 topic、要按 id 拼）、**不用** raw（未解析 OBIS）。
+- DSMR Reader **每秒一条**。本项目按 **10 秒降采样**（仅秒数整 10 落盘）、**整帧存 JSON blob**（不做字段 allowlist）。
+
+### 6.2 telegram JSON 字段（DSMR Reader 配置的 JSON mapping）
+```
+id, timestamp,
+electricity_delivered_1, electricity_delivered_2,        # 进口累计 kWh（_1=dal 低谷, _2=normal 高峰）
+electricity_returned_1,  electricity_returned_2,         # 出口/回送累计 kWh
+electricity_currently_delivered, electricity_currently_returned,   # 瞬时进/出口功率 kW
+phase_currently_delivered_l1/l2/l3, phase_currently_returned_l1/l2/l3,  # 各相瞬时功率 kW
+phase_voltage_l1/l2/l3,                                  # 各相电压 V
+phase_power_current_l1/l2/l3,                            # 各相电流 A
+extra_device_timestamp, extra_device_delivered           # 燃气表（m³，每 5 分钟更新）
+```
+
+### 6.3 实测样本（单相，`dsmr/json`）
+```json
+{
+  "id": 200086230,
+  "timestamp": "2026-06-23T12:16:48Z",
+  "electricity_delivered_1": "20915.154",
+  "electricity_returned_1":  "2979.905",
+  "electricity_delivered_2": "15212.090",
+  "electricity_returned_2":  "6786.406",
+  "electricity_currently_delivered": "0.000",
+  "electricity_currently_returned":  "2.704",
+  "phase_currently_delivered_l1": "0.000",
+  "phase_currently_delivered_l2": null,
+  "phase_currently_delivered_l3": null,
+  "extra_device_timestamp": "2026-06-23T12:15:00Z",
+  "extra_device_delivered": "6208.234",
+  "phase_currently_returned_l1": "2.704",
+  "phase_currently_returned_l2": null,
+  "phase_currently_returned_l3": null,
+  "phase_voltage_l1": "237.0",
+  "phase_voltage_l2": null,
+  "phase_voltage_l3": null
+}
+```
+
+### 6.4 解析要点（实测确认）
+- **数值都是 JSON 字符串**（`"20915.154"`、`"0.000"`）→ 计费读取转 **Decimal**（累计寄存器算钱要精度）。
+- **缺测相位 = `null`**（不是缺 key）→ 视为缺测；单相只有 `*_l1`，三相后 `_l2/_l3` 由 null 变数字。
+- **进口总量** = `electricity_delivered_1 + _2`；**出口总量** = `electricity_returned_1 + _2`（双费率档对动态合同无意义，求和；对固定合同分档计价）。
+- **`timestamp` 为 UTC（Z）**；`id` 自增，做幂等去重。
+- 历史样本里电压 key 曾被错配成带前缀 `dsmr/reading/phase_voltage_l1`（DSMR Reader 的 JSON mapping 配置笔误，用户已改对）——解析仍按"键名容错"。
+- **整表寄存器与相数无关**：`delivered/returned_1/2` 是整表总量，三相只多了各相瞬时通道 → **计费逻辑相数无关**。
+- 燃气 `extra_device_delivered`（m³）一并存入 blob；燃气计费 M6 不做（数据先留，未来按 commodity 扩展）。
+
+---
+
+## 7. 来源 URL
+
+- Tibber GraphQL reference / explorer：`https://developer.tibber.com/docs/reference#rootsubscription`、`https://developer.tibber.com/explorer`
+- Tibber NL 费用构成：`https://support.tibber.com/nl/articles/5605892-de-kosten-bij-tibber`
+- Tibber NL 净计量与回送：`https://support.tibber.com/nl/articles/4669873-salderen-en-terugleveren-bij-tibber`
+- DSMR Reader（HA 集成）：`https://www.home-assistant.io/integrations/dsmr_reader/`
+
+---
+
+## 8. 待真实数据核对（合同生效后用真实 token / 账单）
+
+1. **真实 token 复核**：跑 §1.4 的 15 分钟 curl，确认 NL 返回**真** 15 分钟价（非重复小时价）+ 币种 EUR。
+2. **卖价残差**：确认 `total` 里 purchase fee 是否被卖侧 sales fee 完全抵掉、回送 VAT 口径 → 调 `sell_adjust`（默认 0）。
+3. **双费率寄存器映射**：确认 `_1`=dal/`_2`=normal 没接反（差价小但要对）。
+4. **能源税年值**：按当年实际值与年用电档位核 `energy_tax`。
+5. **固定合同数值**：回送两档价、电网费、heffingskorting 待用户从账单填。
+</content>
@@ -2,7 +2,7 @@

 本文档记录 `home-automation` 在 `v1.0.3` 之后的下一阶段规划。这一阶段不是小修补，而是几次较大的结构性改动：单库化、前端重写、以及远期的移动端试水。

-> 每个里程碑的**可执行原子任务**展开在 [`docs/design/`](./design/README.md)：M1 [`m1-db-consolidation.md`](./design/m1-db-consolidation.md)、M2 [`m2-frontend-v2.md`](./design/m2-frontend-v2.md)、M3 [`m3-token-mobile.md`](./design/m3-token-mobile.md)。这些文档为 Orchestrator→Implementer→Reviewer 的多模型流水线设计。
+> 每个里程碑的**可执行原子任务**展开在 [`docs/design/`](./design/README.md)：M1 [`m1-db-consolidation.md`](./design/m1-db-consolidation.md)、M2 [`m2-frontend-v2.md`](./design/m2-frontend-v2.md)、M3 [`m3-token-mobile.md`](./design/m3-token-mobile.md)、M4 [`m4-login-hardening.md`](./design/m4-login-hardening.md)、M5 [`m5-iot-energy.md`](./design/m5-iot-energy.md)、M6 [`m6-tibber-dynamic-energy.md`](./design/m6-tibber-dynamic-energy.md)、M7 [`m7-meter-epochs-archival.md`](./design/m7-meter-epochs-archival.md)。这些文档为 Orchestrator→Implementer→Reviewer 的多模型流水线设计。

 ## 当前基线（v1.0.3）

@@ -36,9 +36,13 @@
 | --- | --- | --- |
 | **M1** ✅ | 单库化地基 | 把三库合并成单一 `app.db`，清理散落数据层，删掉 Grafana |
 | **M2** ✅ | 前端 v2 | React SPA 取代 Jinja，承载 config + 可视化 + 记录增删改 |
+| **M4** ✅ | 登录加固 | 防爆破/指数退避 + CLI 逃生通道 + 可选 TOTP 二次验证（**先于 M5**） |
+| **M5** ✅ | IoT / 能耗采集 | 通用 Modbus 采集（YAML profile + JSON readings）+ MQTT/HA Discovery + 前端侧边栏 + Energy 视图 |
+| **M6** ✅ | 通用电价层 + DSMR 接入 + 实时电费计算 | 通用电价层（manual/tibber profile + 合同版本）+ DSMR 实时电表接入 + 每 15min 寄存器差×价计量电费（不可变快照）+ 日/月/年汇总 + 反哺 HA Energy + 前端合同/价格/费用视图 |
+| **M7** ✅ | 电表生命周期 / 换表归档 | 引入 Meter epoch，计费永不跨表算 delta，跨表/无表/异常 delta 一律降级，累计按当前表归零，追溯换表可重算，Meter CRUD API + 前端管理 UI |
 | **M3** | 开放与移动端（远期试水） | token 鉴权 + React Native 移动端 |

-排序原则：**先清地基，再在干净结构上盖楼。** M2 的新 API 和 React 必须建立在合并后的单库之上，否则就是在准备推倒的旧数据层上盖新楼、之后回头返工。
+排序原则：**先清地基，再在干净结构上盖楼。** M2 的新 API 和 React 必须建立在合并后的单库之上；M4 是公网安全加固，在 M5 IoT 集成之前先堵住裸密码这个洞；M5 在安全基座就绪后再做 IoT 接入。

 ---

@@ -132,6 +136,127 @@

 ---

+## M4 — 登录加固（✅ 已完成，排在 M5 之前）
+
+### 目标
+
+给暴露在公网的单 admin 登录做纵深防御，先于 M5 IoT 集成关闭暴力枚举和单因子风险。
+
+### 范围
+
+- **防爆破 / 指数退避**：失败登录按双键（IP + username）指数增长延迟，成功即清零。退避是延迟（429 + Retry-After），不是永久封号。全局开关 `AUTH_LOGIN_THROTTLE_ENABLED`（CONFIG_FIELDS）；反代后需开 `AUTH_TRUST_FORWARDED_FOR`（`.env` 部署级）。
+- **CLI 逃生通道**：`python -m scripts.admin_cli` 直连本地 DB，无需 HTTP 服务、无需任何已存凭据；支持重置密码、解锁退避、关停/重发 TOTP、查看用户。
+- **可选 TOTP 二次验证**：admin 可自选启用；启用后两步登录（密码 + 6 位动态码或一次性恢复码）；不启用维持纯密码。CLI `disable-totp` 是连恢复码都丢了时的最终逃生口。
+
+> 详细设计与任务卡：[`docs/design/m4-login-hardening.md`](./design/m4-login-hardening.md)
+
+---
+
+## M5 — IoT 集成与能耗采集（✅ 已完成）
+
+### 目标
+
+给后端接入家庭 IoT 生态，建立通用 Modbus 设备采集链路（首个领域：能耗），接入 MQTT + Home Assistant Discovery，并重构前端为侧边导航并新增 Energy 视图。
+
+### 范围
+
+- **两层数据模型（协议与部署分离）**：YAML profile（随代码走，声明协议知识：寄存器/解码/key/unit/ha_component）+ `modbus_device`（部署层 DB 行：friendly_name/host/port/unit_id/profile/poll_interval/enabled）+ `modbus_reading`（通用遥测：device_id + recorded_at + JSON payload）。多设备可共享同一 profile。
+- **通用 Modbus-TCP 采集**：pymodbus，APScheduler 后台 job 轮询所有 enabled 设备；per-device `last_poll_at`/`last_poll_ok`；全局开关 `MODBUS_POLLING_ENABLED`（CONFIG_FIELDS）。首个 profile：SDM120 单相电表。
+- **手工 CLI 试读**：`scripts/modbus_cli`（`read`/`probe` 两个只读子命令），供受控手工验证，不进自动化。
+- **MQTT + HA Discovery**：paho-mqtt 长连接；通用 expose 框架（provider 动态产出可暴露实体目录，元数据从 YAML profile 派生）；`exposed_entity_toggle` 表存逐 key 开关（默认不暴露）；每设备 = 一个 HA device，各量 = sensor entity + online binary_sensor；`unique_id` 锚定于设备 `uuid`（稳定，不随改名变）；配置变更可重连重发 discovery。
+- **前端侧边栏**：`AppShell` 侧边导航（Home / Records / Energy / Config + 主题切换 + 注销），移动端可折叠，当前路由高亮。
+- **Energy 视图**（`/energy`）：设备 CRUD；最新读数卡片（标签/单位取自 profile metrics 端点）；Recharts 走势图（时间范围 + limit）。
+- **Config 页 Accordion**：各大 section 折叠/展开；「Home Assistant Expose」面板勾选可暴露实体 + 连接状态 + 重新发布按钮。
+- **API**（`/api/modbus/*` + `/api/expose` + `/api/config/mqtt/test`）：完整 CRUD + readings + metrics + test + expose 勾选 + 重发 discovery。
+- `pytest`/`ruff`/`export_openapi` + 前端 `lint/typecheck/test/build` 全绿，`openapi/` 已入库。
+
+### 命名决策（已锁定）
+
+存储/采集/API 全部使用通用 `modbus_*`（`/api/modbus/devices`），**不锁死"电表"**；面向用户的领域呈现叫 **Energy**。接入新 Modbus 设备型号只需新增 YAML profile，无需改表/改 API。
+
+> 详细设计与任务卡：[`docs/design/m5-iot-energy.md`](./design/m5-iot-energy.md)
+
+---
+
+## M6 — 通用电价层 + DSMR 实时数据 + 实时买卖电费计算（✅ 已完成）
+
+### 目标
+
+在 M5 IoT 基建之上，把"电价合同"与"DSMR 实时电表数据"接起来，按 **15 分钟**周期算出**实际买电支出 / 卖电收入**，自己落库留底（不可变、可审计），并通过 MQTT + HA Discovery 反哺 Home Assistant 的 Energy 仪表盘。
+
+### 关键能力
+
+- **通用电价层（两层模型）**：仓库内 YAML profile 定结构（`manual` 固定/双费率、`tibber` 动态电价）；`EnergyContract`（+ 版本）存 UI 可改的数值；price strategy 按 `kind` 出价。一次激活一个合同。改价 = 加新版本，旧版本保留（审计链）。
+- **DSMR 实时数据接入**：扩 `MqttManager` 订阅 `dsmr/json`（每秒一帧），整帧 JSON blob 按 10 秒降采样落库（电、气、各相全存；字段 allowlist 不做，blob 天然容纳未来字段）。
+- **实时买卖电费计算（两层）**：每 15 分钟用电表累计寄存器差值（`delivered_1/2`、`returned_1/2`）× 当时合同的买/卖价算计量电费（不可变、快照价）。买价：tibber = API `total`（含税全包），manual = `energy_buy_档 + energy_tax`；卖价：tibber = `total − energy_tax − sell_adjust`，manual = `sell_档`（无能源税）。双费率：`_1`=dal/低、`_2`=normal/高（NL 惯例）。日/月/年汇总再加固定费（按月→天）减 heffingskorting（按年→天）。不做净计量。卖价残差（sell_adjust）及能源税等当前数值在真实账单确认后钉死。
+- **反哺 Home Assistant**：`_energy_cost_provider` 发 `buy_price_now`、`sell_price_now`、`import_cost_total`（`total_increasing`）、`export_revenue_total`（`total_increasing`）—— 直接挂 HA Energy 仪表盘。
+- **Tibber 动态电价**：httpx GraphQL 客户端抓 `QUARTER_HOURLY` 15 分钟价（已 demo 验证 `total=energy+tax`）；启动 + 每小时抓取今明两天价格、幂等 upsert `tibber_price`（hourly trigger，确保每日刷新且可补重试）；仅当 active 合同 kind=tibber 且 token 存在时运行。
+- **前端**：Energy 视图新增三个 Tab——Contracts（合同管理，表单按 profile 结构渲染）、Prices（15 分钟价格曲线）、Costs（费用走势/明细/汇总卡片）；Config 页 Tibber 测试三态入口。
+
+### 命名分层（延续 M5）
+
+存储/采集/计算层中性命名（`dsmr_*` / `tibber_price` / `energy_cost_period` / `energy_contract`）；面向用户并入既有 **Energy** 视图。
+
+### 新增 5 张表（单库 app 链，migration `20260623_11_energy_tables`）
+
+| 表 | 关键列 | 说明 |
+| --- | --- | --- |
+| `dsmr_reading` | `recorded_at`(idx)、`source_id`(unique)、`payload`(JSON) | 整帧 DSMR telegram blob，10 秒降采样 |
+| `energy_contract` | `name`、`kind`、`active`、`currency`、时间戳 | 合同头；一次一个 active |
+| `energy_contract_version` | `contract_id`(FK)、`effective_from`、`effective_to`(null)、`values`(JSON)、`created_at` | 版本/时段；改价加新版本、旧版本保留 |
+| `tibber_price` | `starts_at`(unique)、`resolution`、`energy/tax/total`、`level`、`currency`、`fetched_at` | 15 分钟价缓存，不可变 |
+| `energy_cost_period` | `period_start`(unique)、`d1/d2/r1/r2_kwh`、`import_cost/export_revenue/net_cost`、`currency`、`pricing`(JSON 快照)、`contract_version_id`(FK)、`degraded`、`computed_at` | 每 15 分钟计量电费，不可变（快照价+版本） |
+
+### 不新增依赖
+
+httpx / paho-mqtt / pyyaml / apscheduler 均为 M5 已有依赖，M6 复用，不新增任何 Python 包。
+
+> 详细设计与任务卡：[`docs/design/m6-tibber-dynamic-energy.md`](./design/m6-tibber-dynamic-energy.md)
+
+---
+
+## M7 — 电表生命周期 / 换表归档（✅ 已完成）
+
+### 目标
+
+让计费系统正确处理**电表更换**这一必然事件：荷兰 2G 智能电表退网后，电网公司会把表换成 4G 表（同址换表）；搬家继承新表也是同类。引入显式的 **Meter（电表）epoch** 概念，标记"某时刻起属于哪一块物理表"，使引擎**永不跨表算 delta**，并让累计量按表归零、历史可追溯可查。
+
+### 关键能力
+
+- **Meter epoch 数据模型**：一条 `meter` 记录 = 一块物理电表的一段安装期 `[started_at, ended_at)`。换表 = 关闭旧 active 表（`ended_at=T`）+ 新建 `started_at=T` 的表。每 `commodity` 至多一个 active 表；`commodity` 字段预留 `gas`/`heating`。
+- **计费永不跨表**：`compute_period` 先查 t0/t1 两端的 `meter_at`；无表覆盖或跨表边界 → **降级**（成本置 0），绝不产负成本或巨额假成本。
+- **delta 护栏**：任一寄存器 delta `< 0` 或 `> _MAX_DELTA_KWH`（100 kWh/15min，远超住宅用量）→ 降级。兜底表重置 / DSMR 回绕 / 数据毛刺，与换表无关的异常也一并防住。
+- **累计按当前表归零（D2）**：`expose.py` 累计 `import_cost_total`/`export_revenue_total` 锚点 = 当前 active electricity meter 的 `started_at`；换表后累计从零起新序列，不维护跨表偏移。
+- **追溯换表可重算**：`started_at` 可在过去；PATCH 修正日期后，触发受影响窗口 `recompute_range` 重判跨表周期归属。
+- **Meter CRUD API + 前端管理 UI**：`GET/POST/PATCH /api/energy/meters`（+ 追溯 recompute）；Energy 页新增 Meters tab，展示电表时间线，支持"换表/继承"表单与编辑。
+
+### 新增表与列（单库 app 链，migration `20260625_13_meter_table`）
+
+| 表/列 | 关键设计 |
+| --- | --- |
+| `meter` | `id`、`label`、`commodity`（默认 `electricity`）、`started_at`、`ended_at`（null=active）、`reason`（`initial`/`meter_swap`/`home_move`/`other`）、`note`、`created_at` |
+| `energy_cost_period.meter_id` | nullable FK → `meter.id`；记录每周期归属，便于审计/按表查询/归档 |
+
+迁移含回填：有历史数据时自动创建一条 `reason="initial"` 的初始表，并回填现有 `energy_cost_period.meter_id`；幂等 + 对账（非降级周期回填后 `meter_id IS NULL` 数必须为 0）。
+
+### 已锁定决策摘要
+
+- **D1**：Meter 不绑定 home，`label` 编址 + `commodity` 区分品类。
+- **D2**：换表后累计量归零（锚当前表起点），不维护跨表偏移。
+- **D3**：合同与电表是独立时间线，合同不引用电表；同址换表时合同自动沿用。
+- **D4**：`started_at` 可在过去；有效计费起点 = `max(started_at, 数据起点)`。
+- **D5**：跨表边界周期判 degraded（换表常伴随长时间无数据，可接受）。
+- **D6**：负/异常大 delta → degraded，通用兜底。
+- **D7**：gas/heating 计费不在本里程碑；`commodity` 字段为未来扩展预留。
+
+**已知行为（可接受）**：累计 `_total` 是 `state_class: total`，换表归零时 HA 长期统计可能在换表那一刻记一次性负 blip。已与用户确认先这样、观察后按需处理（`last_reset` 信号见设计文档 §9 留痕，本里程碑不做）。
+
+> 详细设计与任务卡：[`docs/design/m7-meter-epochs-archival.md`](./design/m7-meter-epochs-archival.md)
+>
+> 模块概念说明：[`docs/meter-epochs.md`](./meter-epochs.md)
+
+---
+
 ## M3 — 开放与移动端（远期试水）

 ### 目标
@@ -149,22 +274,28 @@
 - 移动端是这一阶段最远期、最不确定的部分。
 - token 主要是移动端的前置条件；Web 端 React 用现有 session cookie 即可，不需要为它提前引入 token。

-## Future Ideas（暂不排期，想到先记下）
+## 下一阶段：已确定要做（尚未拆解为任务卡）

-> 这里收集**还没排进里程碑**的想法。不是承诺、也没有先后顺序；想做时再从这里捞出来细化成 `docs/design/` 的任务卡。**明确不开 M2.5**——下列条目一律先躺在 Future Ideas，之后再说。
+> 这些是 M5 之后**已经定下来要做**的方向——区别于下面的 Future Ideas（仅备忘、未必做）。这里只记到 roadmap 粒度：确定**做什么、为什么**；具体排期、依赖与原子任务，等动手时再展开成 `docs/design/` 的任务卡。**先后顺序未定**，具体排期等动手时再定。

-### TOTP 二次验证（Dashboard 加固）
+### 1. 前端优化

-**动机**：M2 之后多了一个 Web Dashboard。它虽有单 admin 密码保护，但**大概率会暴露在公网**上，只靠密码这一层不够。给登录再叠一层 **TOTP（基于时间的一次性密码，RFC 6238）** 作为第二因子，做纵深防御。
+**动机**：M2 的 React SPA 先把功能跑通，性能 / 体验层面的打磨还没做。这一项**确定要做，但具体优化什么还没定**。
+
+**范围（待定）**：方向先留空，想清楚再细化。可能的候选（仅占位、非承诺）：打包体积与代码分割（M2/M5 构建已提示存在 > 500 kB 的单 chunk）、首屏加载、热力图 / 地图的渲染性能、移动端适配、可访问性等。等确定具体目标后再拆任务卡。
+
+### 2. 设置页生成 Long-lived Token（供 API 调用）
+
+**动机**：浏览器端走 session cookie 即可，但**脚本 / 设备 / 外部程序调用 API** 需要一种长期有效、可随身携带的凭据。在设置页加一组功能，由 admin **手动签发 long-lived token**，之后用它来调 API。

 **范围（粗略，待细化）**：

- 在现有单 admin（Argon2 + server-side session）登录之上，叠加 TOTP 第二步：密码校验通过后再验 6 位动态码，通过才发 session cookie。
- 首次启用时生成 TOTP secret，给出可导入 Authenticator 的二维码 / 可手输密钥；同时生成一组一次性**恢复码（recovery codes）**。
+- 设置页新增「API Token」区：生成 / 命名 / 吊销 long-lived token；明文只在**生成时展示一次**，此后只存哈希。
+- 后端支持用该 token 鉴权访问 API（与现有 session cookie 并存，互不影响）。
+- 与 [M3](#m3--开放与移动端远期试水) 的 token 主题相关，但**这条是 Web 设置页手动签发的 PAT 风格**，不依赖移动端 OAuth 流程；两者实现时可复用同一套 token 存储 / 校验。

-**运维 / 命令行要求（关键，实现时必须满足）**：
+## Future Ideas（暂不排期，想到先记下）

-1. **忘记密码**：不需要任何 Web 端“找回密码”流程——直接在命令行里重置 admin 密码即可（沿用现有 CLI 思路）。
-2. **TOTP 重置 / 恢复**：必须提供**命令行重置入口**。要覆盖最坏情况——**连恢复码（restore key）都丢了**，也能纯靠 CLI 把 TOTP 关掉 / 重新发放新的 secret，从而恢复登录。即：**CLI 是不依赖任何已存恢复凭据的最终逃生通道**，不能出现“密钥丢了就彻底锁死”的死角。
+> 这里收集**还没排进里程碑、也还没决定要不要做**的想法。不是承诺、也没有先后顺序；想做时再从这里捞出来——先升进上面的「下一阶段」，再细化成 `docs/design/` 的任务卡。

-**先不做**：本条仅记入 Future Ideas，不进 M2.5、不排期；之后再细化为 design 任务卡。
+_（暂无条目。）_
@@ -17,11 +17,13 @@
        "leaflet.heat": "^0.2.0",
        "leaflet.markercluster": "^1.5.3",
        "openapi-fetch": "^0.17.0",
+        "qrcode.react": "^4.2.0",
        "react": "^18.3.1",
        "react-dom": "^18.3.1",
        "react-feather": "^2.0.10",
        "react-leaflet": "^4.2.1",
-        "react-router-dom": "^6.30.4"
+        "react-router-dom": "^6.30.4",
+        "recharts": "^3.8.1"
      },
      "devDependencies": {
        "@eslint/js": "^9.39.4",
@@ -1445,6 +1447,42 @@
        "node": ">=10"
      }
    },
+    "node_modules/@reduxjs/toolkit": {
+      "version": "2.12.0",
+      "resolved": "https://registry.npmjs.org/@reduxjs/toolkit/-/toolkit-2.12.0.tgz",
+      "integrity": "sha512-KiT+RzZbp6mQET+Mg+h2c97+9j1sNflUxQkIHI7Yuzf6Peu+OYpmkn6nbHWmLLWj+1ZODUJFwGZ7gx3L9R9EOw==",
+      "license": "MIT",
+      "dependencies": {
+        "@standard-schema/spec": "^1.0.0",
+        "@standard-schema/utils": "^0.3.0",
+        "immer": "^11.0.0",
+        "redux": "^5.0.1",
+        "redux-thunk": "^3.1.0",
+        "reselect": "^5.1.0"
+      },
+      "peerDependencies": {
+        "react": "^16.9.0 || ^17.0.0 || ^18 || ^19",
+        "react-redux": "^7.2.1 || ^8.1.3 || ^9.0.0"
+      },
+      "peerDependenciesMeta": {
+        "react": {
+          "optional": true
+        },
+        "react-redux": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@reduxjs/toolkit/node_modules/immer": {
+      "version": "11.1.8",
+      "resolved": "https://registry.npmjs.org/immer/-/immer-11.1.8.tgz",
+      "integrity": "sha512-/tbkHMW7y10Lx6i1crLjD4/OhNkRG+Fo7byZHtah0547nIeXYcpIXaUh0IAQY6gO5459qpGGYapcEOHtFXkIuA==",
+      "license": "MIT",
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/immer"
+      }
+    },
    "node_modules/@remix-run/router": {
      "version": "1.23.3",
      "resolved": "https://registry.npmjs.org/@remix-run/router/-/router-1.23.3.tgz",
@@ -1854,7 +1892,12 @@
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-      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/@standard-schema/utils": {
+      "version": "0.3.0",
+      "resolved": "https://registry.npmjs.org/@standard-schema/utils/-/utils-0.3.0.tgz",
+      "integrity": "sha512-e7Mew686owMaPJVNNLs55PUvgz371nKgwsc4vxE49zsODpJEnxgxRo2y/OKrqueavXgZNMDVj3DdHFlaSAeU8g==",
      "license": "MIT"
    },
    "node_modules/@tanstack/query-core": {
@@ -2057,6 +2100,69 @@
        "assertion-error": "^2.0.1"
      }
    },
+    "node_modules/@types/d3-array": {
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/@types/d3-array/-/d3-array-3.2.2.tgz",
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+      "license": "MIT"
+    },
+    "node_modules/@types/d3-color": {
+      "version": "3.1.3",
+      "resolved": "https://registry.npmjs.org/@types/d3-color/-/d3-color-3.1.3.tgz",
+      "integrity": "sha512-iO90scth9WAbmgv7ogoq57O9YpKmFBbmoEoCHDB2xMBY0+/KVrqAaCDyCE16dUspeOvIxFFRI+0sEtqDqy2b4A==",
+      "license": "MIT"
+    },
+    "node_modules/@types/d3-ease": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/@types/d3-ease/-/d3-ease-3.0.2.tgz",
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+      "license": "MIT"
+    },
+    "node_modules/@types/d3-interpolate": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/@types/d3-interpolate/-/d3-interpolate-3.0.4.tgz",
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+      "license": "MIT",
+      "dependencies": {
+        "@types/d3-color": "*"
+      }
+    },
+    "node_modules/@types/d3-path": {
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/@types/d3-path/-/d3-path-3.1.1.tgz",
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+      "license": "MIT"
+    },
+    "node_modules/@types/d3-scale": {
+      "version": "4.0.9",
+      "resolved": "https://registry.npmjs.org/@types/d3-scale/-/d3-scale-4.0.9.tgz",
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+      "license": "MIT",
+      "dependencies": {
+        "@types/d3-time": "*"
+      }
+    },
+    "node_modules/@types/d3-shape": {
+      "version": "3.1.8",
+      "resolved": "https://registry.npmjs.org/@types/d3-shape/-/d3-shape-3.1.8.tgz",
+      "integrity": "sha512-lae0iWfcDeR7qt7rA88BNiqdvPS5pFVPpo5OfjElwNaT2yyekbM0C9vK+yqBqEmHr6lDkRnYNoTBYlAgJa7a4w==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/d3-path": "*"
+      }
+    },
+    "node_modules/@types/d3-time": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/@types/d3-time/-/d3-time-3.0.4.tgz",
+      "integrity": "sha512-yuzZug1nkAAaBlBBikKZTgzCeA+k1uy4ZFwWANOfKw5z5LRhV0gNA7gNkKm7HoK+HRN0wX3EkxGk0fpbWhmB7g==",
+      "license": "MIT"
+    },
+    "node_modules/@types/d3-timer": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/@types/d3-timer/-/d3-timer-3.0.2.tgz",
+      "integrity": "sha512-Ps3T8E8dZDam6fUyNiMkekK3XUsaUEik+idO9/YjPtfj2qruF8tFBXS7XhtE4iIXBLxhmLjP3SXpLhVf21I9Lw==",
+      "license": "MIT"
+    },
    "node_modules/@types/deep-eql": {
      "version": "4.0.2",
      "resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
@@ -2130,6 +2236,12 @@
        "@types/react": "^18.0.0"
      }
    },
+    "node_modules/@types/use-sync-external-store": {
+      "version": "0.0.6",
+      "resolved": "https://registry.npmjs.org/@types/use-sync-external-store/-/use-sync-external-store-0.0.6.tgz",
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+      "license": "MIT"
+    },
    "node_modules/@typescript-eslint/eslint-plugin": {
      "version": "8.61.0",
      "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-8.61.0.tgz",
@@ -3119,6 +3231,127 @@
      "devOptional": true,
      "license": "MIT"
    },
+    "node_modules/d3-array": {
+      "version": "3.2.4",
+      "resolved": "https://registry.npmjs.org/d3-array/-/d3-array-3.2.4.tgz",
+      "integrity": "sha512-tdQAmyA18i4J7wprpYq8ClcxZy3SC31QMeByyCFyRt7BVHdREQZ5lpzoe5mFEYZUWe+oq8HBvk9JjpibyEV4Jg==",
+      "license": "ISC",
+      "dependencies": {
+        "internmap": "1 - 2"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/d3-color": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/d3-color/-/d3-color-3.1.0.tgz",
+      "integrity": "sha512-zg/chbXyeBtMQ1LbD/WSoW2DpC3I0mpmPdW+ynRTj/x2DAWYrIY7qeZIHidozwV24m4iavr15lNwIwLxRmOxhA==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/d3-ease": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/d3-ease/-/d3-ease-3.0.1.tgz",
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+      "license": "BSD-3-Clause",
+      "engines": {
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+        "d3-format": "1 - 3",
+        "d3-interpolate": "1.2.0 - 3",
+        "d3-time": "2.1.1 - 3",
+        "d3-time-format": "2 - 4"
+      },
+      "engines": {
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+      }
+    },
+    "node_modules/d3-shape": {
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+      "license": "ISC",
+      "dependencies": {
+        "d3-path": "^3.1.0"
+      },
+      "engines": {
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+      }
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+    "node_modules/d3-time": {
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+      "license": "ISC",
+      "dependencies": {
+        "d3-array": "2 - 3"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/d3-time-format": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/d3-time-format/-/d3-time-format-4.1.0.tgz",
+      "integrity": "sha512-dJxPBlzC7NugB2PDLwo9Q8JiTR3M3e4/XANkreKSUxF8vvXKqm1Yfq4Q5dl8budlunRVlUUaDUgFt7eA8D6NLg==",
+      "license": "ISC",
+      "dependencies": {
+        "d3-time": "1 - 3"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/d3-timer": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/d3-timer/-/d3-timer-3.0.1.tgz",
+      "integrity": "sha512-ndfJ/JxxMd3nw31uyKoY2naivF+r29V+Lc0svZxe1JvvIRmi8hUsrMvdOwgS1o6uBHmiz91geQ0ylPP0aj1VUA==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=12"
+      }
+    },
    "node_modules/data-urls": {
      "version": "7.0.0",
      "resolved": "https://registry.npmjs.org/data-urls/-/data-urls-7.0.0.tgz",
@@ -3212,6 +3445,12 @@
      "dev": true,
      "license": "MIT"
    },
+    "node_modules/decimal.js-light": {
+      "version": "2.5.1",
+      "resolved": "https://registry.npmjs.org/decimal.js-light/-/decimal.js-light-2.5.1.tgz",
+      "integrity": "sha512-qIMFpTMZmny+MMIitAB6D7iVPEorVw6YQRWkvarTkT4tBeSLLiHzcwj6q0MmYSFCiVpiqPJTJEYIrpcPzVEIvg==",
+      "license": "MIT"
+    },
    "node_modules/deep-equal": {
      "version": "2.2.3",
      "resolved": "https://registry.npmjs.org/deep-equal/-/deep-equal-2.2.3.tgz",
@@ -3564,6 +3803,16 @@
        "url": "https://github.com/sponsors/ljharb"
      }
    },
+    "node_modules/es-toolkit": {
+      "version": "1.48.1",
+      "resolved": "https://registry.npmjs.org/es-toolkit/-/es-toolkit-1.48.1.tgz",
+      "integrity": "sha512-wfnXlwd5I75eXRtdD2vuEs50xHHESECDsGD7yiQnfFVNoa5522NwXEbmgo98LfiukSQHs+mBM7/YG3qKJB9/mQ==",
+      "license": "MIT",
+      "workspaces": [
+        "docs",
+        "benchmarks"
+      ]
+    },
    "node_modules/esbuild": {
      "version": "0.25.12",
      "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.25.12.tgz",
@@ -3846,6 +4095,12 @@
        "node": ">=0.10.0"
      }
    },
+    "node_modules/eventemitter3": {
+      "version": "5.0.4",
+      "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.4.tgz",
+      "integrity": "sha512-mlsTRyGaPBjPedk6Bvw+aqbsXDtoAyAzm5MO7JgU+yVRyMQ5O8bD4Kcci7BS85f93veegeCPkL8R4GLClnjLFw==",
+      "license": "MIT"
+    },
    "node_modules/expect-type": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.3.0.tgz",
@@ -4311,6 +4566,16 @@
        "node": ">= 4"
      }
    },
+    "node_modules/immer": {
+      "version": "10.2.0",
+      "resolved": "https://registry.npmjs.org/immer/-/immer-10.2.0.tgz",
+      "integrity": "sha512-d/+XTN3zfODyjr89gM3mPq1WNX2B8pYsu7eORitdwyA2sBubnTl3laYlBk4sXY5FUa5qTZGBDPJICVbvqzjlbw==",
+      "license": "MIT",
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/immer"
+      }
+    },
    "node_modules/import-fresh": {
      "version": "3.3.1",
      "resolved": "https://registry.npmjs.org/import-fresh/-/import-fresh-3.3.1.tgz",
@@ -4376,6 +4641,15 @@
        "node": ">= 0.4"
      }
    },
+    "node_modules/internmap": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/internmap/-/internmap-2.0.3.tgz",
+      "integrity": "sha512-5Hh7Y1wQbvY5ooGgPbDaL5iYLAPzMTUrjMulskHLH6wnv/A+1q5rgEaiuqEjB+oxGXIVZs1FF+R/KPN3ZSQYYg==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=12"
+      }
+    },
    "node_modules/is-arguments": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/is-arguments/-/is-arguments-1.2.0.tgz",
@@ -5661,6 +5935,15 @@
        "node": ">=6"
      }
    },
+    "node_modules/qrcode.react": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/qrcode.react/-/qrcode.react-4.2.0.tgz",
+      "integrity": "sha512-QpgqWi8rD9DsS9EP3z7BT+5lY5SFhsqGjpgW5DY/i3mK4M9DTBNz3ErMi8BWYEfI3L0d8GIbGmcdFAS1uIRGjA==",
+      "license": "ISC",
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
    "node_modules/react": {
      "version": "18.3.1",
      "resolved": "https://registry.npmjs.org/react/-/react-18.3.1.tgz",
@@ -5702,7 +5985,6 @@
      "version": "17.0.2",
      "resolved": "https://registry.npmjs.org/react-is/-/react-is-17.0.2.tgz",
      "integrity": "sha512-w2GsyukL62IJnlaff/nRegPQR94C/XXamvMWmSHRJ4y7Ts/4ocGRmTHvOs8PSE6pB3dWOrD/nueuU5sduBsQ4w==",
-      "dev": true,
      "license": "MIT"
    },
    "node_modules/react-leaflet": {
@@ -5729,6 +6011,29 @@
        "react-dom": "^0.14 || ^15.0.0 || ^16.0.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
      }
    },
+    "node_modules/react-redux": {
+      "version": "9.3.0",
+      "resolved": "https://registry.npmjs.org/react-redux/-/react-redux-9.3.0.tgz",
+      "integrity": "sha512-KQopgqFo/p/fgmAs5qz6p5RWaNAzq40WAu7fJIXnQpYxFPbJYtsJPWvGeF2rOBaY/kEuV77AVsX8TsQzKm+A/g==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/use-sync-external-store": "^0.0.6",
+        "use-sync-external-store": "^1.4.0"
+      },
+      "peerDependencies": {
+        "@types/react": "^18.2.25 || ^19",
+        "react": "^18.0 || ^19",
+        "redux": "^5.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "redux": {
+          "optional": true
+        }
+      }
+    },
    "node_modules/react-refresh": {
      "version": "0.17.0",
      "resolved": "https://registry.npmjs.org/react-refresh/-/react-refresh-0.17.0.tgz",
@@ -5857,6 +6162,36 @@
        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
      }
    },
+    "node_modules/recharts": {
+      "version": "3.8.1",
+      "resolved": "https://registry.npmjs.org/recharts/-/recharts-3.8.1.tgz",
+      "integrity": "sha512-mwzmO1s9sFL0TduUpwndxCUNoXsBw3u3E/0+A+cLcrSfQitSG62L32N69GhqUrrT5qKcAE3pCGVINC6pqkBBQg==",
+      "license": "MIT",
+      "workspaces": [
+        "www"
+      ],
+      "dependencies": {
+        "@reduxjs/toolkit": "^1.9.0 || 2.x.x",
+        "clsx": "^2.1.1",
+        "decimal.js-light": "^2.5.1",
+        "es-toolkit": "^1.39.3",
+        "eventemitter3": "^5.0.1",
+        "immer": "^10.1.1",
+        "react-redux": "8.x.x || 9.x.x",
+        "reselect": "5.1.1",
+        "tiny-invariant": "^1.3.3",
+        "use-sync-external-store": "^1.2.2",
+        "victory-vendor": "^37.0.2"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
+        "react-dom": "^16.0.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
+        "react-is": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
    "node_modules/redent": {
      "version": "3.0.0",
      "resolved": "https://registry.npmjs.org/redent/-/redent-3.0.0.tgz",
@@ -5871,6 +6206,21 @@
        "node": ">=8"
      }
    },
+    "node_modules/redux": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/redux/-/redux-5.0.1.tgz",
+      "integrity": "sha512-M9/ELqF6fy8FwmkpnF0S3YKOqMyoWJ4+CS5Efg2ct3oY9daQvd/Pc71FpGZsVsbl3Cpb+IIcjBDUnnyBdQbq4w==",
+      "license": "MIT"
+    },
+    "node_modules/redux-thunk": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/redux-thunk/-/redux-thunk-3.1.0.tgz",
+      "integrity": "sha512-NW2r5T6ksUKXCabzhL9z+h206HQw/NJkcLm1GPImRQ8IzfXwRGqjVhKJGauHirT0DAuyy6hjdnMZaRoAcy0Klw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "redux": "^5.0.0"
+      }
+    },
    "node_modules/reflect.getprototypeof": {
      "version": "1.0.10",
      "resolved": "https://registry.npmjs.org/reflect.getprototypeof/-/reflect.getprototypeof-1.0.10.tgz",
@@ -5925,6 +6275,12 @@
        "node": ">=0.10.0"
      }
    },
+    "node_modules/reselect": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/reselect/-/reselect-5.1.1.tgz",
+      "integrity": "sha512-K/BG6eIky/SBpzfHZv/dd+9JBFiS4SWV7FIujVyJRux6e45+73RaUHXLmIR1f7WOMaQ0U1km6qwklRQxpJJY0w==",
+      "license": "MIT"
+    },
    "node_modules/resolve": {
      "version": "2.0.0-next.7",
      "resolved": "https://registry.npmjs.org/resolve/-/resolve-2.0.0-next.7.tgz",
@@ -6448,6 +6804,12 @@
      "integrity": "sha512-05PUHKSNE8ou2dwIxTngl4EzcnsCDZGJ/iCLtDflR/SHB/ny14rXc+qU5P4mG9JkusiV7EivzY9Mhm55AzAvCg==",
      "license": "MIT"
    },
+    "node_modules/tiny-invariant": {
+      "version": "1.3.3",
+      "resolved": "https://registry.npmjs.org/tiny-invariant/-/tiny-invariant-1.3.3.tgz",
+      "integrity": "sha512-+FbBPE1o9QAYvviau/qC5SE3caw21q3xkvWKBtja5vgqOWIHHJ3ioaq1VPfn/Szqctz2bU/oYeKd9/z5BL+PVg==",
+      "license": "MIT"
+    },
    "node_modules/tinybench": {
      "version": "2.9.0",
      "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
@@ -6863,6 +7225,37 @@
        }
      }
    },
+    "node_modules/use-sync-external-store": {
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/use-sync-external-store/-/use-sync-external-store-1.6.0.tgz",
+      "integrity": "sha512-Pp6GSwGP/NrPIrxVFAIkOQeyw8lFenOHijQWkUTrDvrF4ALqylP2C/KCkeS9dpUM3KvYRQhna5vt7IL95+ZQ9w==",
+      "license": "MIT",
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
+    "node_modules/victory-vendor": {
+      "version": "37.3.6",
+      "resolved": "https://registry.npmjs.org/victory-vendor/-/victory-vendor-37.3.6.tgz",
+      "integrity": "sha512-SbPDPdDBYp+5MJHhBCAyI7wKM3d5ivekigc2Dk2s7pgbZ9wIgIBYGVw4zGHBml/qTFbexrofXW6Gu4noGxrOwQ==",
+      "license": "MIT AND ISC",
+      "dependencies": {
+        "@types/d3-array": "^3.0.3",
+        "@types/d3-ease": "^3.0.0",
+        "@types/d3-interpolate": "^3.0.1",
+        "@types/d3-scale": "^4.0.2",
+        "@types/d3-shape": "^3.1.0",
+        "@types/d3-time": "^3.0.0",
+        "@types/d3-timer": "^3.0.0",
+        "d3-array": "^3.1.6",
+        "d3-ease": "^3.0.1",
+        "d3-interpolate": "^3.0.1",
+        "d3-scale": "^4.0.2",
+        "d3-shape": "^3.1.0",
+        "d3-time": "^3.0.0",
+        "d3-timer": "^3.0.1"
+      }
+    },
    "node_modules/vite": {
      "version": "6.4.3",
      "resolved": "https://registry.npmjs.org/vite/-/vite-6.4.3.tgz",
@@ -22,11 +22,13 @@
    "leaflet.heat": "^0.2.0",
    "leaflet.markercluster": "^1.5.3",
    "openapi-fetch": "^0.17.0",
+    "qrcode.react": "^4.2.0",
    "react": "^18.3.1",
    "react-dom": "^18.3.1",
    "react-feather": "^2.0.10",
    "react-leaflet": "^4.2.1",
-    "react-router-dom": "^6.30.4"
+    "react-router-dom": "^6.30.4",
+    "recharts": "^3.8.1"
  },
  "devDependencies": {
    "@eslint/js": "^9.39.4",
@@ -6,24 +6,20 @@
 *
 * Route tree:
 *   /login            → LoginPage (public)
- *   /change-password  → ProtectedRoute → ChangePasswordPage (T07: forced password change gate)
- *   /                 → ProtectedRoute → AppLayout → HomePage      (T09)
- *   /config           → ProtectedRoute → AppLayout → ConfigPage    (T08)
+ *   /change-password  → ProtectedRoute → ChangePasswordPage (forced password change gate)
+ *   /                 → ProtectedRoute → AppLayout → HomePage
+ *   /config           → ProtectedRoute → AppLayout → ConfigPage
+ *   /records          → ProtectedRoute → AppLayout → RecordsPage
+ *   /energy           → ProtectedRoute → AppLayout → EnergyPage
 *
- * AppLayout renders a nav with a gear-icon entry for /config and a logout button (T07).
+ * AppLayout renders a sidebar (AppSidebar) on the left; page content via <Outlet/> on the right.
+ * /login and /change-password have no sidebar layout.
 */

+import { useState } from 'react'
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { BrowserRouter, Routes, Route, Link, Outlet, useNavigate } from 'react-router-dom'
-import {
-  MantineProvider,
-  Group,
-  ActionIcon,
-  Tooltip,
-  useMantineColorScheme,
-  useComputedColorScheme,
-} from '@mantine/core'
-import { List, Settings, Sun, Moon, LogOut } from 'react-feather'
+import { BrowserRouter, Routes, Route, Outlet } from 'react-router-dom'
+import { MantineProvider, AppShell, Burger } from '@mantine/core'

 // Mantine requires its CSS to be imported once.
 import '@mantine/core/styles.css'
@@ -34,9 +30,9 @@ import { LoginPage } from './pages/LoginPage'
 import { HomePage } from './pages/HomePage'
 import { ConfigPage } from './pages/ConfigPage'
 import { RecordsPage } from './pages/RecordsPage'
+import { EnergyPage } from './pages/EnergyPage'
 import { ChangePasswordPage } from './pages/ChangePasswordPage'
-import apiClient from './api/client'
-import { useQueryClient } from '@tanstack/react-query'
+import { AppSidebar } from './components/AppSidebar'

 // ---------------------------------------------------------------------------
 // TanStack Query client (singleton, created outside render to avoid re-creation)
@@ -57,120 +53,42 @@ const queryClient = new QueryClient({
  },
 })

-// ---------------------------------------------------------------------------
-// Logout button component (needs navigate + queryClient hooks, so it's a component)
-// ---------------------------------------------------------------------------
-
-function LogoutButton() {
-  const navigate = useNavigate()
-  const qc = useQueryClient()
-
-  async function handleLogout() {
-    try {
-      await apiClient.POST('/api/auth/logout')
-    } catch {
-      // Ignore errors on logout — we clear the session regardless.
-    }
-    // Invalidate session so SessionProvider becomes unauthenticated.
-    await qc.invalidateQueries({ queryKey: ['session'] })
-    navigate('/login', { replace: true })
-  }
-
-  return (
-    <Tooltip label="Log out">
-      <ActionIcon
-        variant="default"
-        size="lg"
-        onClick={handleLogout}
-        aria-label="Log out"
-        data-testid="logout-button"
-      >
-        <LogOut size={18} />
-      </ActionIcon>
-    </Tooltip>
-  )
-}
-
-// ---------------------------------------------------------------------------
-// Dark-mode toggle (sits next to the gear / settings icon)
-// ---------------------------------------------------------------------------
-
-function ColorSchemeToggle() {
-  const { setColorScheme } = useMantineColorScheme()
-  const computed = useComputedColorScheme('light', { getInitialValueInEffect: true })
-  const isDark = computed === 'dark'
-  return (
-    <Tooltip label={isDark ? 'Light mode' : 'Dark mode'}>
-      <ActionIcon
-        variant="default"
-        size="lg"
-        aria-label="Toggle color scheme"
-        onClick={() => setColorScheme(isDark ? 'light' : 'dark')}
-        data-testid="color-scheme-toggle"
-      >
-        {isDark ? <Sun size={18} /> : <Moon size={18} />}
-      </ActionIcon>
-    </Tooltip>
-  )
-}
-
 // ---------------------------------------------------------------------------
 // App shell layout (used by all protected pages)
 // ---------------------------------------------------------------------------

 function AppLayout() {
+  // Mobile navbar open/close state — controlled here so the Burger and
+  // AppShell share the same state.
+  const [navbarOpen, setNavbarOpen] = useState(false)
+
  return (
-    <div style={{ minHeight: '100vh', display: 'flex', flexDirection: 'column' }}>
-      {/* Top nav */}
-      <nav
-        style={{
-          display: 'flex',
-          alignItems: 'center',
-          justifyContent: 'space-between',
-          padding: '0.5rem 1rem',
-          borderBottom: '1px solid var(--mantine-color-default-border)',
-        }}
-      >
-        <Link to="/" style={{ fontWeight: 600, textDecoration: 'none' }}>
-          Home Automation
-        </Link>
+    <AppShell
+      navbar={{
+        width: 220,
+        breakpoint: 'sm',
+        collapsed: { mobile: !navbarOpen },
+      }}
+      header={{ height: { base: 48, sm: 0 } }}
+      padding="md"
+    >
+      {/* Burger shown on mobile only (hidden on sm+) */}
+      <AppShell.Header hiddenFrom="sm" p="xs">
+        <Burger
+          opened={navbarOpen}
+          onClick={() => setNavbarOpen((o) => !o)}
+          size="sm"
+          aria-label="Toggle navigation"
+          data-testid="nav-burger"
+        />
+      </AppShell.Header>

-        <Group gap="xs">
-          {/* Records nav link */}
-          <Tooltip label="Records">
-            <ActionIcon
-              component={Link}
-              to="/records"
-              variant="default"
-              size="lg"
-              aria-label="Records"
-            >
-              <List size={18} />
-            </ActionIcon>
-          </Tooltip>
-          {/* Dark-mode toggle — directly beside the settings gear */}
-          <ColorSchemeToggle />
-          {/* Settings — links to config page (§5#10) */}
-          <Tooltip label="Settings">
-            <ActionIcon
-              component={Link}
-              to="/config"
-              variant="default"
-              size="lg"
-              aria-label="Settings"
-            >
-              <Settings size={18} />
-            </ActionIcon>
-          </Tooltip>
-          <LogoutButton />
-        </Group>
-      </nav>
+      <AppSidebar onNavClick={() => setNavbarOpen(false)} />

-      {/* Page content */}
-      <main style={{ flex: 1 }}>
+      <AppShell.Main>
        <Outlet />
-      </main>
-    </div>
+      </AppShell.Main>
+    </AppShell>
  )
 }

@@ -198,7 +116,7 @@ export default function App() {
                }
              />

-              {/* Protected routes — all nested under AppLayout */}
+              {/* Protected routes — all nested under AppLayout (sidebar) */}
              <Route
                element={
                  <ProtectedRoute>
@@ -209,6 +127,7 @@ export default function App() {
                <Route index element={<HomePage />} />
                <Route path="/config" element={<ConfigPage />} />
                <Route path="/records" element={<RecordsPage />} />
+                <Route path="/energy" element={<EnergyPage />} />
              </Route>
            </Routes>
          </SessionProvider>
@@ -0,0 +1,77 @@
+/**
+ * TOTP API helpers (M4-T08).
+ *
+ * All calls go through the typed apiClient (openapi-fetch + generated schema).
+ * CSRF tokens are injected automatically by the client middleware for write
+ * endpoints; GET /api/auth/totp needs no CSRF (read-only).
+ *
+ * Security notes:
+ * - The TotpSetupResponse contains secret + recovery_codes in plaintext.
+ *   These are kept only in component state; callers must NOT write them to
+ *   localStorage, sessionStorage, or log them.
+ * - After the setup phase is over the data leaves memory when the component
+ *   re-renders (one-time display only).
+ */
+
+import apiClient, { ApiError } from '../api/client'
+import type { components } from '../api/schema.d.ts'
+
+export type TotpSetupResponse = components['schemas']['TotpSetupResponse']
+export type TotpStatusResponse = components['schemas']['TotpStatusResponse']
+
+// ---------------------------------------------------------------------------
+// getTotpStatus — GET /api/auth/totp
+// ---------------------------------------------------------------------------
+
+/** Return the current TOTP enabled state for the authenticated user. */
+export async function getTotpStatus(): Promise<TotpStatusResponse> {
+  const res = await apiClient.GET('/api/auth/totp')
+  if (!res.data) {
+    throw new ApiError(res.response.status, null)
+  }
+  return res.data
+}
+
+// ---------------------------------------------------------------------------
+// setupTotp — POST /api/auth/totp/setup
+// ---------------------------------------------------------------------------
+
+/**
+ * Generate a new pending TOTP secret + recovery codes.
+ * Returns the one-time plaintext values; caller is responsible for displaying
+ * them exactly once and never persisting them outside component state.
+ */
+export async function setupTotp(): Promise<TotpSetupResponse> {
+  const res = await apiClient.POST('/api/auth/totp/setup')
+  if (!res.data) {
+    throw new ApiError(res.response.status, null)
+  }
+  return res.data
+}
+
+// ---------------------------------------------------------------------------
+// enableTotp — POST /api/auth/totp/enable
+// ---------------------------------------------------------------------------
+
+/** Confirm TOTP setup with the current 6-digit code from the authenticator app. */
+export async function enableTotp(code: string): Promise<void> {
+  // The endpoint returns 204 on success; openapi-fetch yields { data: undefined }.
+  await apiClient.POST('/api/auth/totp/enable', { body: { code } })
+}
+
+// ---------------------------------------------------------------------------
+// disableTotp — POST /api/auth/totp/disable
+// ---------------------------------------------------------------------------
+
+/**
+ * Disable TOTP.  Exactly one of password or code must be provided.
+ * On success the backend clears the secret and all recovery codes.
+ */
+export async function disableTotp(opts: {
+  password?: string | null
+  code?: string | null
+}): Promise<void> {
+  await apiClient.POST('/api/auth/totp/disable', {
+    body: { password: opts.password ?? null, code: opts.code ?? null },
+  })
+}
@@ -0,0 +1,138 @@
+/**
+ * Tests for AppSidebar (M5-T01, updated M5-T06).
+ *
+ * Strategy: render AppSidebar inside a minimal AppShell (required by
+ * AppShell.Navbar) + MemoryRouter so useLocation() works.
+ *
+ * Coverage:
+ * 1. All four nav items render (Home, Records, Energy, Config).
+ * 2. Home nav item is active when pathname is '/'.
+ * 3. Records nav item is active when pathname is '/records'.
+ * 4. Config nav item is active when pathname is '/config'.
+ * 5. Home is NOT active when on '/records'.
+ * 6. Energy nav item is active when on '/energy'.
+ */
+
+import { describe, it, expect, vi } from 'vitest'
+import { screen } from '@testing-library/react'
+import { render } from '@testing-library/react'
+import { MantineProvider, AppShell } from '@mantine/core'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { MemoryRouter } from 'react-router-dom'
+import { AppSidebar } from './AppSidebar'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient (LogoutButton calls POST /api/auth/logout)
+// ---------------------------------------------------------------------------
+
+vi.mock('../api/client', () => ({
+  default: {
+    POST: vi.fn(),
+    GET: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Helper: render AppSidebar inside the required AppShell + router providers
+// ---------------------------------------------------------------------------
+
+function renderSidebar(initialPath = '/') {
+  const queryClient = new QueryClient({
+    defaultOptions: { queries: { retry: false }, mutations: { retry: false } },
+  })
+
+  return render(
+    <MantineProvider>
+      <QueryClientProvider client={queryClient}>
+        <MemoryRouter initialEntries={[initialPath]}>
+          <AppShell
+            navbar={{ width: 220, breakpoint: 'sm', collapsed: { mobile: false } }}
+            header={{ height: { base: 48, sm: 0 } }}
+          >
+            <AppSidebar />
+          </AppShell>
+        </MemoryRouter>
+      </QueryClientProvider>
+    </MantineProvider>,
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('AppSidebar', () => {
+  // -------------------------------------------------------------------------
+  // 1. All nav items render
+  // -------------------------------------------------------------------------
+
+  it('renders Home, Records, Energy, and Config nav items', () => {
+    renderSidebar('/')
+    expect(screen.getByTestId('nav-home')).toBeInTheDocument()
+    expect(screen.getByTestId('nav-records')).toBeInTheDocument()
+    expect(screen.getByTestId('nav-energy')).toBeInTheDocument()
+    expect(screen.getByTestId('nav-config')).toBeInTheDocument()
+  })
+
+  // -------------------------------------------------------------------------
+  // 2. Home active on '/'
+  // -------------------------------------------------------------------------
+
+  it('marks Home nav item as active when on "/"', () => {
+    renderSidebar('/')
+    // Mantine NavLink sets data-active="true" on the active item
+    const homeLink = screen.getByTestId('nav-home')
+    expect(homeLink).toHaveAttribute('data-active', 'true')
+  })
+
+  // -------------------------------------------------------------------------
+  // 3. Records active on '/records'
+  // -------------------------------------------------------------------------
+
+  it('marks Records nav item as active when on "/records"', () => {
+    renderSidebar('/records')
+    const recordsLink = screen.getByTestId('nav-records')
+    expect(recordsLink).toHaveAttribute('data-active', 'true')
+  })
+
+  // -------------------------------------------------------------------------
+  // 4. Config active on '/config'
+  // -------------------------------------------------------------------------
+
+  it('marks Config nav item as active when on "/config"', () => {
+    renderSidebar('/config')
+    const configLink = screen.getByTestId('nav-config')
+    expect(configLink).toHaveAttribute('data-active', 'true')
+  })
+
+  // -------------------------------------------------------------------------
+  // 5. Home NOT active on '/records' (exact match guard)
+  // -------------------------------------------------------------------------
+
+  it('does NOT mark Home as active when on "/records"', () => {
+    renderSidebar('/records')
+    const homeLink = screen.getByTestId('nav-home')
+    expect(homeLink).not.toHaveAttribute('data-active', 'true')
+  })
+
+  // -------------------------------------------------------------------------
+  // 6. Energy active on '/energy'
+  // -------------------------------------------------------------------------
+
+  it('marks Energy nav item as active when on "/energy"', () => {
+    renderSidebar('/energy')
+    const energyLink = screen.getByTestId('nav-energy')
+    expect(energyLink).toHaveAttribute('data-active', 'true')
+  })
+})
@@ -0,0 +1,171 @@
+/**
+ * AppSidebar — vertical sidebar navigation for all protected pages.
+ *
+ * Nav items: Home / Records / Energy / Config
+ * Utilities: ColorSchemeToggle + LogoutButton (at bottom)
+ *
+ * Current route is highlighted via useLocation().
+ * Mobile: burger button toggles the navbar open/closed (handled by AppShell context).
+ */
+
+import { NavLink, Stack, Divider, Tooltip, ActionIcon, useMantineColorScheme, useComputedColorScheme, AppShell, Text, Group } from '@mantine/core'
+import { Link, useLocation, useNavigate } from 'react-router-dom'
+import { Home, List, Settings, Sun, Moon, LogOut, Zap } from 'react-feather'
+import { useQueryClient } from '@tanstack/react-query'
+import apiClient from '../api/client'
+
+// ---------------------------------------------------------------------------
+// Individual nav entries
+// ---------------------------------------------------------------------------
+
+interface NavEntry {
+  to: string
+  label: string
+  icon: React.ReactNode
+  testId: string
+}
+
+const NAV_ENTRIES: NavEntry[] = [
+  {
+    to: '/',
+    label: 'Home',
+    icon: <Home size={18} />,
+    testId: 'nav-home',
+  },
+  {
+    to: '/records',
+    label: 'Records',
+    icon: <List size={18} />,
+    testId: 'nav-records',
+  },
+  {
+    to: '/energy',
+    label: 'Energy',
+    icon: <Zap size={18} />,
+    testId: 'nav-energy',
+  },
+  {
+    to: '/config',
+    label: 'Config',
+    icon: <Settings size={18} />,
+    testId: 'nav-config',
+  },
+]
+
+// ---------------------------------------------------------------------------
+// Colour-scheme toggle
+// ---------------------------------------------------------------------------
+
+function ColorSchemeToggle() {
+  const { setColorScheme } = useMantineColorScheme()
+  const computed = useComputedColorScheme('light', { getInitialValueInEffect: true })
+  const isDark = computed === 'dark'
+  return (
+    <Tooltip label={isDark ? 'Light mode' : 'Dark mode'} position="right">
+      <ActionIcon
+        variant="default"
+        size="lg"
+        aria-label="Toggle color scheme"
+        onClick={() => setColorScheme(isDark ? 'light' : 'dark')}
+        data-testid="color-scheme-toggle"
+      >
+        {isDark ? <Sun size={18} /> : <Moon size={18} />}
+      </ActionIcon>
+    </Tooltip>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Logout button
+// ---------------------------------------------------------------------------
+
+function LogoutButton() {
+  const navigate = useNavigate()
+  const qc = useQueryClient()
+
+  async function handleLogout() {
+    try {
+      await apiClient.POST('/api/auth/logout')
+    } catch {
+      // Ignore errors — clear session regardless.
+    }
+    await qc.invalidateQueries({ queryKey: ['session'] })
+    navigate('/login', { replace: true })
+  }
+
+  return (
+    <Tooltip label="Log out" position="right">
+      <ActionIcon
+        variant="default"
+        size="lg"
+        onClick={handleLogout}
+        aria-label="Log out"
+        data-testid="logout-button"
+      >
+        <LogOut size={18} />
+      </ActionIcon>
+    </Tooltip>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Sidebar
+// ---------------------------------------------------------------------------
+
+interface AppSidebarProps {
+  /** Called when a nav link is clicked on mobile (to close the navbar). */
+  onNavClick?: () => void
+}
+
+export function AppSidebar({ onNavClick }: AppSidebarProps) {
+  const location = useLocation()
+
+  return (
+    <AppShell.Navbar p="xs">
+      {/* App title */}
+      <AppShell.Section>
+        <Group px="xs" py="sm">
+          <Text fw={700} size="sm" component={Link} to="/" style={{ textDecoration: 'none' }}>
+            Home Automation
+          </Text>
+        </Group>
+        <Divider />
+      </AppShell.Section>
+
+      {/* Navigation links */}
+      <AppShell.Section grow mt="sm">
+        <Stack gap={4}>
+          {NAV_ENTRIES.map(({ to, label, icon, testId }) => {
+            // For the home route "/" we need an exact match; others prefix-match is fine.
+            const isActive =
+              to === '/'
+                ? location.pathname === '/'
+                : location.pathname.startsWith(to)
+
+            return (
+              <NavLink
+                key={to}
+                component={Link}
+                to={to}
+                label={label}
+                leftSection={icon}
+                active={isActive}
+                data-testid={testId}
+                onClick={onNavClick}
+              />
+            )
+          })}
+        </Stack>
+      </AppShell.Section>
+
+      {/* Bottom utilities: theme toggle + logout */}
+      <AppShell.Section>
+        <Divider mb="xs" />
+        <Group gap="xs" px="xs" pb="xs">
+          <ColorSchemeToggle />
+          <LogoutButton />
+        </Group>
+      </AppShell.Section>
+    </AppShell.Navbar>
+  )
+}
@@ -0,0 +1,381 @@
+/**
+ * Tests for ExposeSettings (M5-T12).
+ *
+ * Strategy: vi.mock the apiClient so GET/PUT/POST responses are controlled
+ * without a real server or MQTT broker.
+ *
+ * Coverage:
+ * 1. Loading state shows a loader.
+ * 2. Error state shows an error alert.
+ * 3. Empty catalog shows the empty-state message.
+ * 4. Catalog with entities: renders entity names, device groups, toggle switches.
+ * 5. MQTT status badges render correctly (configured/connected/discovery).
+ * 6. Toggling a switch calls PUT /api/expose with the correct key/bool.
+ * 7. Re-publish button calls POST /api/expose/republish.
+ * 8. Republish ok=true shows success alert; ok=false shows warning.
+ * 9. value_getter is never rendered (no crash from non-serialisable callable).
+ * 10. binary_sensor entities are shown in the catalog alongside sensors.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor, fireEvent } from '@testing-library/react'
+import { renderWithProviders } from '../test-utils'
+import { ExposeSettings } from './ExposeSettings'
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const MOCK_MQTT_STATUS_OFF = {
+  mqtt_configured: false,
+  mqtt_connected: false,
+  discovery_enabled: false,
+}
+
+const MOCK_MQTT_STATUS_ON = {
+  mqtt_configured: true,
+  mqtt_connected: true,
+  discovery_enabled: true,
+}
+
+const MOCK_CATALOG_EMPTY = {
+  catalog: [],
+  mqtt_status: MOCK_MQTT_STATUS_OFF,
+}
+
+const MOCK_CATALOG_ONE_DEVICE = {
+  catalog: [
+    {
+      entity: {
+        key: 'modbus.abc.voltage',
+        component: 'sensor',
+        device: { identifiers: ['modbus', 'abc'], name: 'Test Meter' },
+        device_class: 'voltage',
+        unit: 'V',
+        name: 'Test Meter Voltage',
+        state_class: 'measurement',
+      },
+      enabled: false,
+    },
+    {
+      entity: {
+        key: 'modbus.abc.current',
+        component: 'sensor',
+        device: { identifiers: ['modbus', 'abc'], name: 'Test Meter' },
+        device_class: 'current',
+        unit: 'A',
+        name: 'Test Meter Current',
+        state_class: 'measurement',
+      },
+      enabled: true,
+    },
+    {
+      entity: {
+        key: 'modbus.abc.online',
+        component: 'binary_sensor',
+        device: { identifiers: ['modbus', 'abc'], name: 'Test Meter' },
+        device_class: 'connectivity',
+        unit: '',
+        name: 'Test Meter Online',
+        state_class: null,
+      },
+      enabled: false,
+    },
+  ],
+  mqtt_status: MOCK_MQTT_STATUS_ON,
+}
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPut = vi.fn()
+const mockPost = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    PUT: (...args: unknown[]) => mockPut(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Helper
+// ---------------------------------------------------------------------------
+
+function renderExpose() {
+  return renderWithProviders(<ExposeSettings />, { initialPath: '/config' })
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('ExposeSettings', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  // -------------------------------------------------------------------------
+  // 1. Loading state
+  // -------------------------------------------------------------------------
+
+  it('shows a loader while the catalog is loading', () => {
+    // Never resolves
+    mockGet.mockReturnValue(new Promise(() => {}))
+    renderExpose()
+    expect(screen.getByTestId('expose-loading')).toBeInTheDocument()
+  })
+
+  // -------------------------------------------------------------------------
+  // 2. Error state
+  // -------------------------------------------------------------------------
+
+  it('shows an error alert when the catalog request fails', async () => {
+    mockGet.mockRejectedValue(new Error('Network error'))
+    renderExpose()
+    await waitFor(() => {
+      expect(screen.getByTestId('expose-load-error')).toBeInTheDocument()
+    })
+  })
+
+  // -------------------------------------------------------------------------
+  // 3. Empty catalog
+  // -------------------------------------------------------------------------
+
+  it('shows empty-state message when catalog is empty', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_EMPTY })
+    renderExpose()
+    await waitFor(() => {
+      expect(screen.getByTestId('expose-empty')).toBeInTheDocument()
+    })
+  })
+
+  // -------------------------------------------------------------------------
+  // 4. Catalog with entities
+  // -------------------------------------------------------------------------
+
+  it('renders entity names and device groups', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('expose-settings')).toBeInTheDocument()
+    })
+
+    // Device group heading
+    expect(screen.getByTestId('device-group-Test Meter')).toBeInTheDocument()
+
+    // Entity names
+    expect(screen.getByText('Test Meter Voltage')).toBeInTheDocument()
+    expect(screen.getByText('Test Meter Current')).toBeInTheDocument()
+    expect(screen.getByText('Test Meter Online')).toBeInTheDocument()
+  })
+
+  it('renders toggle switches for each entity', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('entity-toggle-modbus.abc.voltage')).toBeInTheDocument()
+    })
+
+    // voltage is disabled (enabled=false in fixture)
+    const voltageSwitch = screen.getByTestId(
+      'entity-toggle-modbus.abc.voltage',
+    ) as HTMLInputElement
+    expect(voltageSwitch.checked).toBe(false)
+
+    // current is enabled (enabled=true in fixture)
+    const currentSwitch = screen.getByTestId(
+      'entity-toggle-modbus.abc.current',
+    ) as HTMLInputElement
+    expect(currentSwitch.checked).toBe(true)
+  })
+
+  it('shows binary_sensor entities alongside sensor entities', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('entity-row-modbus.abc.online')).toBeInTheDocument()
+    })
+
+    // binary_sensor row contains "binary_sensor" text
+    const onlineRow = screen.getByTestId('entity-row-modbus.abc.online')
+    expect(onlineRow).toHaveTextContent('binary_sensor')
+  })
+
+  // -------------------------------------------------------------------------
+  // 5. MQTT status badges
+  // -------------------------------------------------------------------------
+
+  it('renders MQTT status badges', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('mqtt-status-badges')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('badge-mqtt-configured')).toBeInTheDocument()
+    expect(screen.getByTestId('badge-mqtt-connected')).toBeInTheDocument()
+    expect(screen.getByTestId('badge-discovery-enabled')).toBeInTheDocument()
+  })
+
+  it('shows "Configured" when mqtt_configured is true', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('badge-mqtt-configured')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('badge-mqtt-configured')).toHaveTextContent('MQTT Configured')
+  })
+
+  it('shows "Not Configured" when mqtt_configured is false', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_EMPTY })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('badge-mqtt-configured')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('badge-mqtt-configured')).toHaveTextContent('MQTT Not Configured')
+  })
+
+  // -------------------------------------------------------------------------
+  // 6. Toggle a switch → PUT /api/expose
+  // -------------------------------------------------------------------------
+
+  it('calls PUT /api/expose when a toggle is switched', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    mockPut.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('entity-toggle-modbus.abc.voltage')).toBeInTheDocument()
+    })
+
+    // Click the voltage toggle (currently off → turning on)
+    const voltageSwitch = screen.getByTestId('entity-toggle-modbus.abc.voltage')
+    fireEvent.click(voltageSwitch)
+
+    await waitFor(() => {
+      expect(mockPut).toHaveBeenCalled()
+    })
+
+    const putCall = mockPut.mock.calls[0]
+    // path arg
+    expect(putCall[0]).toBe('/api/expose')
+    // body
+    expect(putCall[1]?.body?.toggles).toMatchObject({ 'modbus.abc.voltage': true })
+  })
+
+  // -------------------------------------------------------------------------
+  // 7. Republish button → POST /api/expose/republish
+  // -------------------------------------------------------------------------
+
+  it('calls POST /api/expose/republish when republish button is clicked', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    mockPost.mockResolvedValue({ data: { ok: true, message: 'HA Discovery re-published.' } })
+
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('republish-button')).toBeInTheDocument()
+    })
+
+    fireEvent.click(screen.getByTestId('republish-button'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalled()
+    })
+
+    const postCall = mockPost.mock.calls[0]
+    expect(postCall[0]).toBe('/api/expose/republish')
+  })
+
+  // -------------------------------------------------------------------------
+  // 8. Republish ok=true → success alert; ok=false → warning
+  // -------------------------------------------------------------------------
+
+  it('shows success alert when republish returns ok=true', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    mockPost.mockResolvedValue({
+      data: { ok: true, message: 'HA Discovery re-published successfully.' },
+    })
+
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('republish-button')).toBeInTheDocument()
+    })
+
+    fireEvent.click(screen.getByTestId('republish-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('republish-success')).toBeInTheDocument()
+    })
+    expect(screen.queryByTestId('republish-warning')).not.toBeInTheDocument()
+  })
+
+  it('shows warning alert when republish returns ok=false', async () => {
+    mockGet.mockResolvedValue({ data: MOCK_CATALOG_ONE_DEVICE })
+    mockPost.mockResolvedValue({
+      data: { ok: false, message: 'MQTT not connected.' },
+    })
+
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('republish-button')).toBeInTheDocument()
+    })
+
+    fireEvent.click(screen.getByTestId('republish-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('republish-warning')).toBeInTheDocument()
+    })
+    expect(screen.queryByTestId('republish-success')).not.toBeInTheDocument()
+  })
+
+  // -------------------------------------------------------------------------
+  // 9. No crash from non-serialisable value_getter (value_getter NOT rendered)
+  // -------------------------------------------------------------------------
+
+  it('renders without crashing even if value_getter were present (it is excluded by API)', async () => {
+    // The API never sends value_getter; this tests resilience of the schema
+    const catalogWithExtraField = {
+      ...MOCK_CATALOG_ONE_DEVICE,
+      catalog: MOCK_CATALOG_ONE_DEVICE.catalog.map((entry) => ({
+        ...entry,
+        entity: { ...entry.entity },
+        // No value_getter — confirm the component handles normal data
+      })),
+    }
+    mockGet.mockResolvedValue({ data: catalogWithExtraField })
+    renderExpose()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('expose-settings')).toBeInTheDocument()
+    })
+    // No errors thrown, entities visible
+    expect(screen.getByText('Test Meter Voltage')).toBeInTheDocument()
+  })
+})
@@ -0,0 +1,303 @@
+/**
+ * ExposeSettings — Home Assistant Expose entity management (M5-T12).
+ *
+ * Behaviours:
+ * 1. Load: GET /api/expose → display catalog of exposable entities grouped by HA device,
+ *    with per-entity toggle switches and MQTT/Discovery connection status badges.
+ * 2. Toggle: PUT /api/expose with the changed key → bool; triggers discovery re-publish.
+ * 3. Republish: POST /api/expose/republish → manually trigger HA Discovery re-publish.
+ *
+ * All requests go through the typed apiClient (CSRF injected automatically by
+ * csrfMiddleware for write operations).
+ */
+
+import { useState } from 'react'
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
+import {
+  Alert,
+  Badge,
+  Button,
+  Center,
+  Group,
+  Loader,
+  Stack,
+  Switch,
+  Text,
+} from '@mantine/core'
+import apiClient from '../api/client'
+import type { components } from '../api/schema.d.ts'
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+type CatalogEntry = components['schemas']['CatalogEntrySchema']
+type MqttStatus = components['schemas']['MqttStatusSchema']
+
+// ---------------------------------------------------------------------------
+// Hook: load expose catalog
+// ---------------------------------------------------------------------------
+
+function useExposeCatalog() {
+  return useQuery({
+    queryKey: ['expose-catalog'],
+    queryFn: async () => {
+      const res = await apiClient.GET('/api/expose')
+      return res.data
+    },
+  })
+}
+
+// ---------------------------------------------------------------------------
+// Hook: toggle a single entity
+// ---------------------------------------------------------------------------
+
+function useToggleEntity() {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: async ({ key, enabled }: { key: string; enabled: boolean }) => {
+      await apiClient.PUT('/api/expose', {
+        body: { toggles: { [key]: enabled } },
+      })
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['expose-catalog'] }),
+  })
+}
+
+// ---------------------------------------------------------------------------
+// Hook: republish discovery
+// ---------------------------------------------------------------------------
+
+function useRepublish() {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: async () => {
+      const res = await apiClient.POST('/api/expose/republish')
+      return res.data
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['expose-catalog'] }),
+  })
+}
+
+// ---------------------------------------------------------------------------
+// MqttStatusBadges — connection status indicators
+// ---------------------------------------------------------------------------
+
+function MqttStatusBadges({ status }: { status: MqttStatus }) {
+  return (
+    <Group gap="xs" wrap="wrap" data-testid="mqtt-status-badges">
+      <Badge
+        color={status.mqtt_configured ? 'blue' : 'gray'}
+        variant="outline"
+        size="sm"
+        data-testid="badge-mqtt-configured"
+      >
+        MQTT {status.mqtt_configured ? 'Configured' : 'Not Configured'}
+      </Badge>
+      <Badge
+        color={status.mqtt_connected ? 'green' : 'red'}
+        variant="outline"
+        size="sm"
+        data-testid="badge-mqtt-connected"
+      >
+        {status.mqtt_connected ? 'Connected' : 'Disconnected'}
+      </Badge>
+      <Badge
+        color={status.discovery_enabled ? 'teal' : 'gray'}
+        variant="outline"
+        size="sm"
+        data-testid="badge-discovery-enabled"
+      >
+        Discovery {status.discovery_enabled ? 'On' : 'Off'}
+      </Badge>
+    </Group>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// EntityRow — one entity toggle row
+// ---------------------------------------------------------------------------
+
+interface EntityRowProps {
+  entry: CatalogEntry
+  onToggle: (key: string, enabled: boolean) => void
+  isToggling: boolean
+}
+
+function EntityRow({ entry, onToggle, isToggling }: EntityRowProps) {
+  const { entity, enabled } = entry
+  return (
+    <Group justify="space-between" gap="sm" wrap="nowrap" data-testid={`entity-row-${entity.key}`}>
+      <Stack gap={2}>
+        <Text size="sm" fw={500}>
+          {entity.name}
+        </Text>
+        <Text size="xs" c="dimmed">
+          {entity.component}
+          {entity.device_class ? ` · ${entity.device_class}` : ''}
+          {entity.unit ? ` · ${entity.unit}` : ''}
+        </Text>
+      </Stack>
+      <Switch
+        checked={enabled}
+        onChange={(e) => onToggle(entity.key, e.currentTarget.checked)}
+        disabled={isToggling}
+        size="sm"
+        data-testid={`entity-toggle-${entity.key}`}
+      />
+    </Group>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// DeviceGroup — entities grouped by device name
+// ---------------------------------------------------------------------------
+
+interface DeviceGroupProps {
+  deviceName: string
+  entries: CatalogEntry[]
+  onToggle: (key: string, enabled: boolean) => void
+  isToggling: boolean
+}
+
+function DeviceGroup({ deviceName, entries, onToggle, isToggling }: DeviceGroupProps) {
+  return (
+    <Stack gap="xs" data-testid={`device-group-${deviceName}`}>
+      <Text fw={600} size="sm" c="dimmed">
+        {deviceName}
+      </Text>
+      {entries.map((entry) => (
+        <EntityRow
+          key={entry.entity.key}
+          entry={entry}
+          onToggle={onToggle}
+          isToggling={isToggling}
+        />
+      ))}
+    </Stack>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// RepublishButton — POST /api/expose/republish
+// ---------------------------------------------------------------------------
+
+function RepublishButton() {
+  const [result, setResult] = useState<{ ok: boolean; message: string } | null>(null)
+  const republishMutation = useRepublish()
+
+  async function handleRepublish() {
+    setResult(null)
+    try {
+      const data = await republishMutation.mutateAsync()
+      if (data) {
+        setResult({ ok: data.ok, message: data.message })
+      }
+    } catch {
+      setResult({ ok: false, message: 'Republish request failed.' })
+    }
+  }
+
+  return (
+    <Stack gap="xs">
+      <Button
+        type="button"
+        variant="outline"
+        size="sm"
+        onClick={handleRepublish}
+        loading={republishMutation.isPending}
+        data-testid="republish-button"
+      >
+        Re-publish Discovery
+      </Button>
+
+      {result?.ok && (
+        <Alert color="green" data-testid="republish-success">
+          {result.message}
+        </Alert>
+      )}
+      {result !== null && !result.ok && (
+        <Alert color="orange" data-testid="republish-warning">
+          {result.message}
+        </Alert>
+      )}
+    </Stack>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// ExposeSettings — main exported component
+// ---------------------------------------------------------------------------
+
+export function ExposeSettings() {
+  const { data, isLoading, isError } = useExposeCatalog()
+  const toggleMutation = useToggleEntity()
+
+  function handleToggle(key: string, enabled: boolean) {
+    toggleMutation.mutate({ key, enabled })
+  }
+
+  if (isLoading) {
+    return (
+      <Center pt="md">
+        <Loader size="sm" data-testid="expose-loading" />
+      </Center>
+    )
+  }
+
+  if (isError || !data) {
+    return (
+      <Alert color="red" data-testid="expose-load-error">
+        Failed to load expose settings. Please refresh the page.
+      </Alert>
+    )
+  }
+
+  // Defensive null-coerce in case the data shape is unexpected at runtime.
+  const catalog = data.catalog ?? []
+  const mqtt_status = data.mqtt_status ?? {
+    mqtt_configured: false,
+    mqtt_connected: false,
+    discovery_enabled: false,
+  }
+
+  // Group entities by device name for display.
+  const deviceGroups = new Map<string, CatalogEntry[]>()
+  for (const entry of catalog) {
+    const deviceName = entry.entity.device.name
+    const existing = deviceGroups.get(deviceName)
+    if (existing) {
+      existing.push(entry)
+    } else {
+      deviceGroups.set(deviceName, [entry])
+    }
+  }
+
+  return (
+    <Stack gap="md" data-testid="expose-settings">
+      {/* Status row */}
+      <Group justify="space-between" align="center" wrap="wrap" gap="sm">
+        <MqttStatusBadges status={mqtt_status} />
+        <RepublishButton />
+      </Group>
+
+      {/* Entity catalog — empty state */}
+      {catalog.length === 0 && (
+        <Text c="dimmed" size="sm" data-testid="expose-empty">
+          No exposable entities found. Add a Modbus device in the Energy page to get started.
+        </Text>
+      )}
+
+      {/* Entity catalog — grouped by device */}
+      {Array.from(deviceGroups.entries()).map(([deviceName, entries]) => (
+        <DeviceGroup
+          key={deviceName}
+          deviceName={deviceName}
+          entries={entries}
+          onToggle={handleToggle}
+          isToggling={toggleMutation.isPending}
+        />
+      ))}
+    </Stack>
+  )
+}
@@ -0,0 +1,338 @@
+/**
+ * Tests for ContractForm component.
+ *
+ * Coverage:
+ * 1. Renders profile fields dynamically from profile structure (not hardcoded)
+ *    — verified by passing defaultKind so fields render automatically.
+ * 2. Submit in create mode calls POST /api/energy/contracts.
+ * 3. Submit in add-version mode calls POST /api/energy/contracts/{id}/versions.
+ * 4. Cancel closes modal.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { renderWithProviders } from '../test-utils'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: vi.fn(),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const PROFILES_RESPONSE = {
+  profiles: [
+    {
+      kind: 'manual',
+      label: 'Fixed / Variable Rate (NL, dual-tariff)',
+      energy: {
+        dual_tariff: true,
+        buy: { normal: { unit: 'EUR/kWh' }, dal: { unit: 'EUR/kWh' } },
+        sell: { normal: { unit: 'EUR/kWh' }, dal: { unit: 'EUR/kWh' } },
+        energy_tax: { unit: 'EUR/kWh' },
+        ode: { unit: 'EUR/kWh', default: 0 },
+      },
+      standing: {
+        network_fee: { unit: 'EUR/month' },
+        management_fee: { unit: 'EUR/month' },
+      },
+      credits: {
+        heffingskorting: { unit: 'EUR/year' },
+      },
+    },
+  ],
+}
+
+const CREATED_CONTRACT = {
+  id: 1,
+  name: 'Test Contract',
+  kind: 'manual',
+  active: false,
+  currency: 'EUR',
+  created_at: '2026-06-01T00:00:00Z',
+  updated_at: '2026-06-01T00:00:00Z',
+  versions: [],
+}
+
+// ---------------------------------------------------------------------------
+// Import component
+// ---------------------------------------------------------------------------
+
+import { ContractForm } from './ContractForm'
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('ContractForm', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders profile fields dynamically from profile structure (not hardcoded)', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    const onClose = vi.fn()
+    const onSaved = vi.fn()
+
+    // Pass defaultKind so the profile fields render automatically in create mode
+    renderWithProviders(
+      <ContractForm defaultKind="manual" onClose={onClose} onSaved={onSaved} />,
+    )
+
+    // Wait for profiles to load and fields to appear
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-section-energy')).toBeInTheDocument()
+    }, { timeout: 3000 })
+
+    // Verify sections are rendered from profile structure (not hardcoded)
+    expect(screen.getByTestId('contract-section-energy')).toBeInTheDocument()
+    expect(screen.getByTestId('contract-section-standing')).toBeInTheDocument()
+    expect(screen.getByTestId('contract-section-credits')).toBeInTheDocument()
+
+    // Verify specific fields exist from the profile structure
+    // "energy.buy.normal" → label "Buy Normal"
+    expect(screen.getByTestId('contract-field-energy.buy.normal')).toBeInTheDocument()
+    expect(screen.getByTestId('contract-field-energy.buy.dal')).toBeInTheDocument()
+    expect(screen.getByTestId('contract-field-standing.network_fee')).toBeInTheDocument()
+  })
+
+  it('calls POST /api/energy/contracts in create mode', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      return Promise.resolve({ data: null })
+    })
+    mockPost.mockResolvedValue({ data: CREATED_CONTRACT })
+
+    const onClose = vi.fn()
+    const onSaved = vi.fn()
+
+    // Use defaultKind to ensure fields load without needing to interact with Select
+    renderWithProviders(
+      <ContractForm defaultKind="manual" onClose={onClose} onSaved={onSaved} />,
+    )
+
+    // Wait for form to render
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-form')).toBeInTheDocument()
+    })
+
+    // Wait for profile fields to appear
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-name')).toBeInTheDocument()
+    })
+
+    // Fill in contract name
+    await user.type(screen.getByTestId('contract-name'), 'Test Contract')
+
+    // Submit form
+    await user.click(screen.getByTestId('contract-form-submit'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/energy/contracts',
+        expect.objectContaining({
+          body: expect.objectContaining({
+            name: 'Test Contract',
+            kind: 'manual',
+            currency: 'EUR',
+          }),
+        }),
+      )
+    }, { timeout: 3000 })
+  })
+
+  it('calls POST /api/energy/contracts/{id}/versions in add-version mode', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      return Promise.resolve({ data: null })
+    })
+    mockPost.mockResolvedValue({ data: CREATED_CONTRACT })
+
+    const onClose = vi.fn()
+    const onSaved = vi.fn()
+
+    renderWithProviders(
+      <ContractForm contractId={1} defaultKind="manual" onClose={onClose} onSaved={onSaved} />,
+    )
+
+    // Wait for form to be ready (add-version mode)
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-form')).toBeInTheDocument()
+    })
+
+    // In add-version mode, no name or kind fields shown
+    expect(screen.queryByTestId('contract-name')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('contract-kind')).not.toBeInTheDocument()
+
+    // Fill in effective_from (required in add-version mode)
+    const effectiveDateInput = screen.getByTestId('contract-effective-from')
+    await user.type(effectiveDateInput, '2026-07-01')
+
+    // Submit form
+    await user.click(screen.getByTestId('contract-form-submit'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/energy/contracts/{contract_id}/versions',
+        expect.objectContaining({
+          params: { path: { contract_id: 1 } },
+          body: expect.objectContaining({
+            values: expect.any(Object),
+          }),
+        }),
+      )
+    }, { timeout: 3000 })
+  })
+
+  it('calls onClose when Cancel button is clicked', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    const onClose = vi.fn()
+    const onSaved = vi.fn()
+
+    renderWithProviders(
+      <ContractForm onClose={onClose} onSaved={onSaved} />,
+    )
+
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-form-cancel')).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId('contract-form-cancel'))
+
+    expect(onClose).toHaveBeenCalled()
+  })
+
+  it('prefills fields from the open version when in add-version mode', async () => {
+    // FU11: add-version mode should auto-prefill rate fields from the contract's
+    // current open version so the user only has to change what's different.
+    const CONTRACT_DETAIL = {
+      id: 42,
+      name: 'My Contract',
+      kind: 'manual',
+      active: true,
+      currency: 'EUR',
+      created_at: '2026-01-01T00:00:00Z',
+      updated_at: '2026-01-01T00:00:00Z',
+      versions: [
+        {
+          id: 1,
+          contract_id: 42,
+          effective_from: '2026-01-01T00:00:00Z',
+          effective_to: null,  // open version
+          values: {
+            energy: {
+              buy: { normal: 0.133, dal: 0.127 },
+              sell: { normal: 0.05, dal: 0.05 },
+              energy_tax: 0.11,
+              ode: 0.0,
+            },
+            standing: {
+              network_fee: 30.0,
+              management_fee: 60.0,
+            },
+            credits: {
+              heffingskorting: 365.0,
+            },
+          },
+          created_at: '2026-01-01T00:00:00Z',
+        },
+      ],
+    }
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      if (path === '/api/energy/contracts/{contract_id}') {
+        return Promise.resolve({ data: CONTRACT_DETAIL })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    const onClose = vi.fn()
+    const onSaved = vi.fn()
+
+    renderWithProviders(
+      <ContractForm contractId={42} defaultKind="manual" onClose={onClose} onSaved={onSaved} />,
+    )
+
+    const user = userEvent.setup()
+
+    // Wait for the form to render and profile fields to appear
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-section-energy')).toBeInTheDocument()
+    }, { timeout: 3000 })
+
+    // Wait for prefill to apply: both profile and contract detail queries must resolve.
+    // Fill in the required effective_from date and submit; the submitted values
+    // body.values should contain the prefilled rates from the open version.
+    mockPost.mockResolvedValue({ data: {} })
+
+    const effectiveInput = screen.getByTestId('contract-effective-from')
+    await user.type(effectiveInput, '2026-07-01')
+
+    await user.click(screen.getByTestId('contract-form-submit'))
+
+    // The submitted body should contain the prefilled values from CONTRACT_DETAIL
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/energy/contracts/{contract_id}/versions',
+        expect.objectContaining({
+          body: expect.objectContaining({
+            values: expect.objectContaining({
+              standing: expect.objectContaining({
+                network_fee: 30,
+                management_fee: 60,
+              }),
+            }),
+          }),
+        }),
+      )
+    }, { timeout: 3000 })
+  })
+})
@@ -0,0 +1,466 @@
+/**
+ * ContractForm — create a new energy contract OR add a version to an existing one.
+ *
+ * Form fields are dynamically rendered from the profile structure returned by
+ * GET /api/energy/profiles — never hardcoded.  The profile structure provides
+ * section names (energy, standing, credits), leaf keys, and their units.
+ *
+ * Create mode: show Name, Kind (Select from profiles), Currency, optional
+ *   effective_from, then dynamically rendered profile value fields.
+ * Add-version mode (contractId provided): show only effective_from (required)
+ *   + profile value fields for the contract's kind.
+ */
+
+import { useState, useMemo } from 'react'
+import {
+  Modal,
+  Stack,
+  TextInput,
+  NumberInput,
+  Select,
+  Button,
+  Group,
+  Alert,
+  Loader,
+  Center,
+  Text,
+  Divider,
+  Title,
+} from '@mantine/core'
+import { useEnergyProfiles, useCreateContract, useAddContractVersion, useContractDetail } from './hooks'
+
+// ---------------------------------------------------------------------------
+// Props
+// ---------------------------------------------------------------------------
+
+export interface ContractFormProps {
+  /** When provided: add-version mode; contract must exist. */
+  contractId?: number
+  /** Existing contract kind (for add-version mode or edit). */
+  defaultKind?: string
+  onClose: () => void
+  onSaved: () => void
+}
+
+// ---------------------------------------------------------------------------
+// Helpers for dynamic profile field rendering
+// ---------------------------------------------------------------------------
+
+/**
+ * A leaf in the profile structure is any object with a `unit` key.
+ * Returns true if the value is a leaf (renderable field).
+ */
+function isLeaf(val: unknown): val is { unit: string; default?: unknown } {
+  return typeof val === 'object' && val !== null && 'unit' in val
+}
+
+/**
+ * Extract all leaf fields from a profile section, returning
+ * [dotPath, unit, defaultValue] tuples. E.g.:
+ *   "energy.buy.normal" → "EUR/kWh"
+ *   "energy.energy_tax" → "EUR/kWh"
+ */
+interface LeafField {
+  /** Dot-separated path within the section, e.g. "buy.normal" */
+  fieldPath: string
+  unit: string
+  defaultValue?: number
+}
+
+function extractLeafFields(obj: Record<string, unknown>, prefix = ''): LeafField[] {
+  const fields: LeafField[] = []
+  for (const [key, val] of Object.entries(obj)) {
+    // Skip non-object values (e.g. dual_tariff: true)
+    if (typeof val !== 'object' || val === null) continue
+    const path = prefix ? `${prefix}.${key}` : key
+    if (isLeaf(val)) {
+      fields.push({
+        fieldPath: path,
+        unit: val.unit,
+        defaultValue: typeof val.default === 'number' ? val.default : undefined,
+      })
+    } else {
+      fields.push(...extractLeafFields(val as Record<string, unknown>, path))
+    }
+  }
+  return fields
+}
+
+/**
+ * Build a nested values object from flat field values.
+ * E.g. { "buy.normal": 0.133, "buy.dal": 0.127 } → { buy: { normal: 0.133, dal: 0.127 } }
+ */
+function buildNestedValues(
+  sectionFields: Record<string, LeafField[]>,
+  fieldValues: Record<string, number | string>,
+): Record<string, unknown> {
+  const result: Record<string, unknown> = {}
+
+  for (const [section, fields] of Object.entries(sectionFields)) {
+    const sectionObj: Record<string, unknown> = {}
+    for (const field of fields) {
+      const raw = fieldValues[`${section}.${field.fieldPath}`]
+      const numVal = typeof raw === 'number' ? raw : parseFloat(String(raw))
+      // Set nested path
+      const parts = field.fieldPath.split('.')
+      let current = sectionObj
+      for (let i = 0; i < parts.length - 1; i++) {
+        if (!(parts[i] in current)) current[parts[i]] = {}
+        current = current[parts[i]] as Record<string, unknown>
+      }
+      current[parts[parts.length - 1]] = isNaN(numVal) ? 0 : numVal
+    }
+    result[section] = sectionObj
+  }
+
+  return result
+}
+
+/**
+ * Label formatter: converts "buy.normal" → "Buy Normal", "energy_tax" → "Energy Tax"
+ */
+function formatLabel(path: string): string {
+  return path
+    .replace(/\./g, ' ')
+    .replace(/_/g, ' ')
+    .replace(/\b\w/g, (c) => c.toUpperCase())
+}
+
+// ---------------------------------------------------------------------------
+// Component
+// ---------------------------------------------------------------------------
+
+export function ContractForm({ contractId, defaultKind, onClose, onSaved }: ContractFormProps) {
+  const isAddVersion = contractId != null
+
+  // Profiles query
+  const profilesQuery = useEnergyProfiles()
+
+  // Contract detail query — only used in add-version mode to prefill from the open version.
+  const contractDetailQuery = useContractDetail(contractId ?? 0)
+
+  // Create mode fields
+  const [name, setName] = useState('')
+  const [selectedKind, setSelectedKind] = useState<string | null>(defaultKind ?? null)
+  const [currency, setCurrency] = useState('EUR')
+  // ISO date string "YYYY-MM-DD" for effective_from; empty = default to now
+  const [effectiveFromStr, setEffectiveFromStr] = useState('')
+
+  // Dynamic profile field values: key = "<section>.<fieldPath>", value = number.
+  // User edits are stored here; for add-version mode this is merged with prefillValues.
+  const [userEdits, setUserEdits] = useState<Record<string, number | string>>({})
+
+  const [error, setError] = useState<string | null>(null)
+
+  const createMutation = useCreateContract()
+  const addVersionMutation = useAddContractVersion()
+
+  const isBusy = createMutation.isPending || addVersionMutation.isPending
+
+  // Resolve the effective kind (add-version mode uses defaultKind)
+  const effectiveKind = isAddVersion ? (defaultKind ?? null) : selectedKind
+
+  // Build profile options from API response
+  const profiles = profilesQuery.data?.profiles ?? []
+  const profileOptions = profiles.map((p: Record<string, unknown>) => ({
+    value: p.kind as string,
+    label: (p.label as string | undefined) ?? (p.kind as string),
+  }))
+
+  // Find the selected profile structure
+  const selectedProfile = profiles.find((p: Record<string, unknown>) => p.kind === effectiveKind)
+
+  // Extract section → leaf fields mapping from the selected profile (memoized for stable reference).
+  const sectionFields = useMemo<Record<string, LeafField[]>>(() => {
+    if (!selectedProfile) return {}
+    const profileObj = selectedProfile as Record<string, unknown>
+    const result: Record<string, LeafField[]> = {}
+    for (const [key, val] of Object.entries(profileObj)) {
+      if (key === 'kind' || key === 'label') continue
+      if (typeof val === 'object' && val !== null && !isLeaf(val)) {
+        result[key] = extractLeafFields(val as Record<string, unknown>)
+      }
+    }
+    return result
+  }, [selectedProfile])
+
+  // Add-version prefill: compute the seeded values from the contract's open version.
+  // Returns the flat fieldValues dict or null when data is not ready.
+  const prefillValues = useMemo<Record<string, number | string> | null>(() => {
+    if (!isAddVersion) return null
+    if (contractDetailQuery.isLoading || contractDetailQuery.isError) return null
+    if (Object.keys(sectionFields).length === 0) return null
+
+    const detail = contractDetailQuery.data
+    if (!detail || !detail.versions || detail.versions.length === 0) return null
+
+    const versions = detail.versions as Array<{
+      effective_from: string
+      effective_to: string | null
+      values: Record<string, unknown>
+    }>
+    let openVersion = versions.find((v) => v.effective_to == null)
+    if (!openVersion) {
+      openVersion = [...versions].sort((a, b) =>
+        a.effective_from < b.effective_from ? 1 : -1
+      )[0]
+    }
+    if (!openVersion?.values) return null
+
+    const seeded: Record<string, number | string> = {}
+    for (const [section, fields] of Object.entries(sectionFields)) {
+      const sectionVal = (openVersion.values as Record<string, unknown>)[section]
+      if (typeof sectionVal !== 'object' || sectionVal === null) continue
+      for (const leaf of fields) {
+        const parts = leaf.fieldPath.split('.')
+        let cursor: unknown = sectionVal
+        for (const part of parts) {
+          if (typeof cursor !== 'object' || cursor === null) { cursor = undefined; break }
+          cursor = (cursor as Record<string, unknown>)[part]
+        }
+        if (cursor != null && (typeof cursor === 'number' || typeof cursor === 'string')) {
+          const numVal = typeof cursor === 'number' ? cursor : parseFloat(String(cursor))
+          seeded[`${section}.${leaf.fieldPath}`] = isNaN(numVal) ? 0 : numVal
+        }
+      }
+    }
+    return Object.keys(seeded).length > 0 ? seeded : null
+  }, [
+    isAddVersion,
+    contractDetailQuery.isLoading,
+    contractDetailQuery.isError,
+    contractDetailQuery.data,
+    sectionFields,
+  ])
+
+  // The effective field values: user edits override prefill; prefill is the base.
+  // In add-version mode: when the user has not yet edited any field (userEdits is empty),
+  // prefillValues is used as the initial base.  Once the user edits any field, their
+  // full merged value (prefill + override) is stored in userEdits.
+  const fieldValues: Record<string, number | string> =
+    isAddVersion && prefillValues !== null && Object.keys(userEdits).length === 0
+      ? prefillValues
+      : userEdits
+
+  function handleFieldChange(key: string, val: number | string) {
+    // On first edit in add-version mode, copy prefill into userEdits so we don't
+    // lose the other prefilled values when the user changes one field.
+    setUserEdits((prev) => {
+      const base = isAddVersion && prefillValues !== null && Object.keys(prev).length === 0
+        ? { ...prefillValues }
+        : prev
+      return { ...base, [key]: val }
+    })
+  }
+
+  // Initialize default values when profile changes (create mode only)
+  function initDefaults(kind: string | null) {
+    if (!kind) return
+    const profile = profiles.find((p: Record<string, unknown>) => p.kind === kind)
+    if (!profile) return
+    const profileObj = profile as Record<string, unknown>
+    const defaults: Record<string, number | string> = {}
+    for (const [sectionKey, sectionVal] of Object.entries(profileObj)) {
+      if (sectionKey === 'kind' || sectionKey === 'label') continue
+      if (typeof sectionVal === 'object' && sectionVal !== null && !isLeaf(sectionVal)) {
+        const leaves = extractLeafFields(sectionVal as Record<string, unknown>)
+        for (const leaf of leaves) {
+          defaults[`${sectionKey}.${leaf.fieldPath}`] = leaf.defaultValue ?? 0
+        }
+      }
+    }
+    setUserEdits(defaults)
+  }
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setError(null)
+
+    if (!isAddVersion && !name.trim()) {
+      setError('Contract name is required.')
+      return
+    }
+    if (!effectiveKind) {
+      setError('Contract kind is required.')
+      return
+    }
+
+    const values = buildNestedValues(sectionFields, fieldValues)
+
+    try {
+      // Convert local date string to a naive local-midnight datetime string (no Z).
+      // The backend interprets naive datetimes as server local wall-clock time,
+      // so "2026-06-25T00:00:00" → CEST local midnight → stored as UTC 22:00Z.
+      // When effectiveFromStr is empty, fall back to the current instant (aware,
+      // sent as ISO with Z) so the backend stores it unchanged.
+      const effectiveFromISO = effectiveFromStr
+        ? `${effectiveFromStr}T00:00:00`
+        : undefined
+
+      if (isAddVersion) {
+        const body = {
+          effective_from: effectiveFromISO ?? new Date().toISOString(),
+          values,
+        }
+        await addVersionMutation.mutateAsync({ id: contractId, body })
+      } else {
+        const body = {
+          name: name.trim(),
+          kind: effectiveKind,
+          currency,
+          values,
+          ...(effectiveFromISO ? { effective_from: effectiveFromISO } : {}),
+        }
+        await createMutation.mutateAsync(body)
+      }
+      onSaved()
+      onClose()
+    } catch {
+      setError('Failed to save. Please try again.')
+    }
+  }
+
+  // ---------------------------------------------------------------------------
+  // Render
+  // ---------------------------------------------------------------------------
+
+  const title = isAddVersion ? 'Add Contract Version' : 'New Energy Contract'
+
+  return (
+    <Modal
+      opened
+      onClose={onClose}
+      title={title}
+      size="md"
+      data-testid="contract-form-modal"
+    >
+      {(profilesQuery.isLoading || (isAddVersion && contractDetailQuery.isLoading)) && (
+        <Center py="md">
+          <Loader size="sm" data-testid="contract-form-loading" />
+        </Center>
+      )}
+
+      {profilesQuery.isError && (
+        <Alert color="red" mb="sm" data-testid="contract-form-profiles-error">
+          Failed to load pricing profiles. Cannot continue.
+        </Alert>
+      )}
+
+      {isAddVersion && contractDetailQuery.isError && !contractDetailQuery.isLoading && (
+        <Alert color="yellow" mb="sm" data-testid="contract-form-detail-error">
+          Could not load existing contract values for prefill — fields start at 0.
+        </Alert>
+      )}
+
+      {!profilesQuery.isLoading && !(isAddVersion && contractDetailQuery.isLoading) && (
+        <form onSubmit={handleSubmit} data-testid="contract-form">
+          <Stack gap="sm">
+            {/* Create mode fields */}
+            {!isAddVersion && (
+              <>
+                <TextInput
+                  label="Contract name"
+                  required
+                  value={name}
+                  onChange={(e) => setName(e.currentTarget.value)}
+                  data-testid="contract-name"
+                />
+
+                <Select
+                  label="Pricing kind"
+                  required
+                  data={profileOptions}
+                  value={selectedKind}
+                  onChange={(val) => {
+                    setSelectedKind(val)
+                    initDefaults(val)
+                  }}
+                  data-testid="contract-kind"
+                />
+
+                <TextInput
+                  label="Currency"
+                  value={currency}
+                  onChange={(e) => setCurrency(e.currentTarget.value)}
+                  data-testid="contract-currency"
+                />
+              </>
+            )}
+
+            {/* Effective from — required for add-version, optional for create */}
+            <TextInput
+              label={isAddVersion ? 'Effective from (required)' : 'Effective from (optional, defaults to now)'}
+              description="Date in YYYY-MM-DD format"
+              type="date"
+              required={isAddVersion}
+              value={effectiveFromStr}
+              onChange={(e) => setEffectiveFromStr(e.currentTarget.value)}
+              data-testid="contract-effective-from"
+            />
+
+            {/* Dynamic profile fields */}
+            {effectiveKind && Object.keys(sectionFields).length > 0 && (
+              <>
+                <Divider mt="xs" />
+                {Object.entries(sectionFields).map(([section, fields]) => (
+                  <Stack key={section} gap="xs" data-testid={`contract-section-${section}`}>
+                    <Title order={6} tt="capitalize" c="dimmed">
+                      {section.replace(/_/g, ' ')}
+                    </Title>
+                    {fields.map((field) => {
+                      const key = `${section}.${field.fieldPath}`
+                      const raw = fieldValues[key]
+                      const numVal = typeof raw === 'number' ? raw : parseFloat(String(raw))
+                      return (
+                        <NumberInput
+                          key={key}
+                          label={formatLabel(field.fieldPath)}
+                          description={field.unit}
+                          value={isNaN(numVal) ? 0 : numVal}
+                          onChange={(val) => handleFieldChange(key, val)}
+                          decimalScale={6}
+                          step={0.001}
+                          data-testid={`contract-field-${key}`}
+                        />
+                      )
+                    })}
+                  </Stack>
+                ))}
+              </>
+            )}
+
+            {!effectiveKind && !isAddVersion && (
+              <Text size="sm" c="dimmed" data-testid="contract-form-kind-hint">
+                Select a pricing kind to see the rate fields.
+              </Text>
+            )}
+
+            {error && (
+              <Alert color="red" data-testid="contract-form-error">
+                {error}
+              </Alert>
+            )}
+
+            <Group justify="flex-end" gap="sm">
+              <Button
+                type="button"
+                variant="default"
+                onClick={onClose}
+                data-testid="contract-form-cancel"
+              >
+                Cancel
+              </Button>
+              <Button
+                type="submit"
+                loading={isBusy}
+                data-testid="contract-form-submit"
+              >
+                {isAddVersion ? 'Add Version' : 'Create Contract'}
+              </Button>
+            </Group>
+          </Stack>
+        </form>
+      )}
+    </Modal>
+  )
+}
@@ -0,0 +1,205 @@
+/**
+ * Tests for ContractManager component.
+ *
+ * Coverage:
+ * 1. Loading state rendering.
+ * 2. Contract list rendering.
+ * 3. Empty state rendering.
+ * 4. Activate button calls PATCH with {active: true}.
+ * 5. "New Contract" button opens ContractForm.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { renderWithProviders } from '../test-utils'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+const mockPatch = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: (...args: unknown[]) => mockPatch(...args),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const ACTIVE_CONTRACT = {
+  id: 1,
+  name: 'My Active Contract',
+  kind: 'manual',
+  active: true,
+  currency: 'EUR',
+  created_at: '2026-06-01T00:00:00Z',
+  updated_at: '2026-06-01T00:00:00Z',
+}
+
+const INACTIVE_CONTRACT = {
+  id: 2,
+  name: 'Inactive Contract',
+  kind: 'tibber',
+  active: false,
+  currency: 'EUR',
+  created_at: '2026-06-02T00:00:00Z',
+  updated_at: '2026-06-02T00:00:00Z',
+}
+
+const PROFILES_RESPONSE = {
+  profiles: [
+    {
+      kind: 'manual',
+      label: 'Fixed / Variable Rate (NL, dual-tariff)',
+      energy: {
+        dual_tariff: true,
+        buy: { normal: { unit: 'EUR/kWh' }, dal: { unit: 'EUR/kWh' } },
+        sell: { normal: { unit: 'EUR/kWh' }, dal: { unit: 'EUR/kWh' } },
+        energy_tax: { unit: 'EUR/kWh' },
+        ode: { unit: 'EUR/kWh', default: 0 },
+      },
+      standing: {
+        network_fee: { unit: 'EUR/month' },
+        management_fee: { unit: 'EUR/month' },
+      },
+      credits: {
+        heffingskorting: { unit: 'EUR/year' },
+      },
+    },
+  ],
+}
+
+// ---------------------------------------------------------------------------
+// Import component
+// ---------------------------------------------------------------------------
+
+import { ContractManager } from './ContractManager'
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('ContractManager', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders loading state initially', () => {
+    // Never resolve so we stay in loading state
+    mockGet.mockImplementation(() => new Promise(() => {}))
+
+    renderWithProviders(<ContractManager />)
+
+    expect(screen.getByTestId('contracts-loading')).toBeInTheDocument()
+  })
+
+  it('renders contract list when data loads', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/contracts') {
+        return Promise.resolve({
+          data: { items: [ACTIVE_CONTRACT, INACTIVE_CONTRACT], total: 2 },
+        })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<ContractManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('contracts-table')).toBeInTheDocument()
+    })
+
+    expect(screen.getByText('My Active Contract')).toBeInTheDocument()
+    expect(screen.getByText('Inactive Contract')).toBeInTheDocument()
+    expect(screen.getByTestId('contract-active-badge-1')).toHaveTextContent('active')
+    expect(screen.getByTestId('contract-active-badge-2')).toHaveTextContent('inactive')
+  })
+
+  it('renders empty state when no contracts exist', async () => {
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    renderWithProviders(<ContractManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('contracts-empty')).toBeInTheDocument()
+    })
+  })
+
+  it('calls PATCH with active=true when Activate button clicked', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/contracts') {
+        return Promise.resolve({
+          data: { items: [INACTIVE_CONTRACT], total: 1 },
+        })
+      }
+      return Promise.resolve({ data: null })
+    })
+    mockPatch.mockResolvedValue({
+      data: { ...INACTIVE_CONTRACT, active: true, versions: [] },
+    })
+
+    renderWithProviders(<ContractManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`contract-activate-${INACTIVE_CONTRACT.id}`)).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId(`contract-activate-${INACTIVE_CONTRACT.id}`))
+
+    await waitFor(() => {
+      expect(mockPatch).toHaveBeenCalledWith(
+        '/api/energy/contracts/{contract_id}',
+        expect.objectContaining({
+          params: { path: { contract_id: INACTIVE_CONTRACT.id } },
+          body: { active: true },
+        }),
+      )
+    })
+  })
+
+  it('opens ContractForm when "New Contract" button is clicked', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/contracts') {
+        return Promise.resolve({ data: { items: [], total: 0 } })
+      }
+      if (path === '/api/energy/profiles') {
+        return Promise.resolve({ data: PROFILES_RESPONSE })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<ContractManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-new-button')).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId('contract-new-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('contract-form-modal')).toBeInTheDocument()
+    })
+  })
+})
@@ -0,0 +1,331 @@
+/**
+ * ContractManager — energy contract list UI.
+ *
+ * Features:
+ * - Table of contracts: name, kind, active badge, currency, created date, actions.
+ * - Actions per row: Activate (PATCH active=true), Add Version, View History.
+ * - "New Contract" button at top.
+ * - Version history modal showing all versions with effective dates and values.
+ * - Loading / error / empty states.
+ */
+
+import { useState } from 'react'
+import {
+  Table,
+  Button,
+  Group,
+  Text,
+  Loader,
+  Center,
+  Alert,
+  Stack,
+  Badge,
+  ScrollArea,
+  Modal,
+  Accordion,
+  Code,
+} from '@mantine/core'
+import {
+  useContracts,
+  useUpdateContract,
+  type ContractResponse,
+  type ContractDetailResponse,
+} from './hooks'
+import { ContractForm } from './ContractForm'
+import apiClient from '../api/client'
+import { formatLocalDate } from '../utils/datetime'
+
+// ---------------------------------------------------------------------------
+// Version history modal
+// ---------------------------------------------------------------------------
+
+interface VersionHistoryModalProps {
+  contractId: number
+  contractName: string
+  onClose: () => void
+}
+
+function VersionHistoryModal({ contractId, contractName, onClose }: VersionHistoryModalProps) {
+  const [loading, setLoading] = useState(true)
+  const [detail, setDetail] = useState<ContractDetailResponse | null>(null)
+  const [fetchError, setFetchError] = useState<string | null>(null)
+
+  // Fetch detail on first render
+  useState(() => {
+    apiClient
+      .GET('/api/energy/contracts/{contract_id}', {
+        params: { path: { contract_id: contractId } },
+      })
+      .then((res) => {
+        setDetail(res.data ?? null)
+        setLoading(false)
+      })
+      .catch(() => {
+        setFetchError('Failed to load contract details.')
+        setLoading(false)
+      })
+  })
+
+  return (
+    <Modal
+      opened
+      onClose={onClose}
+      title={`Version history — ${contractName}`}
+      size="lg"
+      data-testid="version-history-modal"
+    >
+      {loading && (
+        <Center py="md">
+          <Loader size="sm" />
+        </Center>
+      )}
+      {fetchError && (
+        <Alert color="red" data-testid="version-history-error">
+          {fetchError}
+        </Alert>
+      )}
+      {!loading && !fetchError && detail && (
+        <>
+          {detail.versions.length === 0 ? (
+            <Text c="dimmed" ta="center" size="sm" data-testid="version-history-empty">
+              No versions found.
+            </Text>
+          ) : (
+            <Accordion variant="separated" data-testid="version-history-accordion">
+              {detail.versions.map((v) => (
+                <Accordion.Item key={v.id} value={String(v.id)} data-testid={`version-item-${v.id}`}>
+                  <Accordion.Control>
+                    <Group gap="sm">
+                      <Text size="sm" fw={500}>
+                        From: {formatLocalDate(v.effective_from)}
+                      </Text>
+                      {v.effective_to ? (
+                        <Text size="xs" c="dimmed">
+                          To: {formatLocalDate(v.effective_to)}
+                        </Text>
+                      ) : (
+                        <Badge color="green" size="xs">
+                          current
+                        </Badge>
+                      )}
+                    </Group>
+                  </Accordion.Control>
+                  <Accordion.Panel>
+                    <Code block style={{ fontSize: 11 }}>
+                      {JSON.stringify(v.values, null, 2)}
+                    </Code>
+                  </Accordion.Panel>
+                </Accordion.Item>
+              ))}
+            </Accordion>
+          )}
+        </>
+      )}
+      <Group justify="flex-end" mt="md">
+        <Button variant="default" onClick={onClose}>
+          Close
+        </Button>
+      </Group>
+    </Modal>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Contract table
+// ---------------------------------------------------------------------------
+
+interface ContractTableProps {
+  contracts: ContractResponse[]
+  onActivate: (id: number) => void
+  onAddVersion: (contract: ContractResponse) => void
+  onViewHistory: (contract: ContractResponse) => void
+  activatingId: number | null
+}
+
+function ContractTable({
+  contracts,
+  onActivate,
+  onAddVersion,
+  onViewHistory,
+  activatingId,
+}: ContractTableProps) {
+  if (contracts.length === 0) {
+    return (
+      <Text c="dimmed" ta="center" size="sm" data-testid="contracts-empty">
+        No contracts configured yet. Click "New Contract" to add one.
+      </Text>
+    )
+  }
+
+  return (
+    <ScrollArea>
+      <Table striped highlightOnHover withTableBorder data-testid="contracts-table">
+        <Table.Thead>
+          <Table.Tr>
+            <Table.Th>Name</Table.Th>
+            <Table.Th>Kind</Table.Th>
+            <Table.Th>Active</Table.Th>
+            <Table.Th>Currency</Table.Th>
+            <Table.Th>Created</Table.Th>
+            <Table.Th style={{ textAlign: 'right' }}>Actions</Table.Th>
+          </Table.Tr>
+        </Table.Thead>
+        <Table.Tbody>
+          {contracts.map((contract) => (
+            <Table.Tr key={contract.id} data-testid={`contract-row-${contract.id}`}>
+              <Table.Td>
+                <Text fw={500} size="sm">
+                  {contract.name}
+                </Text>
+              </Table.Td>
+              <Table.Td>
+                <Badge variant="outline" size="sm">
+                  {contract.kind}
+                </Badge>
+              </Table.Td>
+              <Table.Td>
+                <Badge
+                  color={contract.active ? 'green' : 'gray'}
+                  variant="light"
+                  size="sm"
+                  data-testid={`contract-active-badge-${contract.id}`}
+                >
+                  {contract.active ? 'active' : 'inactive'}
+                </Badge>
+              </Table.Td>
+              <Table.Td>{contract.currency}</Table.Td>
+              <Table.Td>
+                <Text size="xs" c="dimmed">
+                  {formatLocalDate(contract.created_at)}
+                </Text>
+              </Table.Td>
+              <Table.Td>
+                <Group justify="flex-end" gap="xs">
+                  {!contract.active && (
+                    <Button
+                      size="xs"
+                      variant="outline"
+                      color="green"
+                      loading={activatingId === contract.id}
+                      onClick={() => onActivate(contract.id)}
+                      data-testid={`contract-activate-${contract.id}`}
+                    >
+                      Activate
+                    </Button>
+                  )}
+                  <Button
+                    size="xs"
+                    variant="outline"
+                    onClick={() => onAddVersion(contract)}
+                    data-testid={`contract-add-version-${contract.id}`}
+                  >
+                    Add Version
+                  </Button>
+                  <Button
+                    size="xs"
+                    variant="subtle"
+                    onClick={() => onViewHistory(contract)}
+                    data-testid={`contract-history-${contract.id}`}
+                  >
+                    History
+                  </Button>
+                </Group>
+              </Table.Td>
+            </Table.Tr>
+          ))}
+        </Table.Tbody>
+      </Table>
+    </ScrollArea>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// ContractManager — top-level
+// ---------------------------------------------------------------------------
+
+export function ContractManager() {
+  const contractsQuery = useContracts()
+  const updateMutation = useUpdateContract()
+
+  const [showCreateForm, setShowCreateForm] = useState(false)
+  const [addVersionContract, setAddVersionContract] = useState<ContractResponse | null>(null)
+  const [historyContract, setHistoryContract] = useState<ContractResponse | null>(null)
+  const [activatingId, setActivatingId] = useState<number | null>(null)
+
+  async function handleActivate(id: number) {
+    setActivatingId(id)
+    try {
+      await updateMutation.mutateAsync({ id, body: { active: true } })
+    } finally {
+      setActivatingId(null)
+    }
+  }
+
+  // ---------------------------------------------------------------------------
+  // Render states
+  // ---------------------------------------------------------------------------
+
+  if (contractsQuery.isLoading) {
+    return (
+      <Center py="xl" data-testid="contracts-loading">
+        <Loader />
+      </Center>
+    )
+  }
+
+  if (contractsQuery.isError || !contractsQuery.data) {
+    return (
+      <Alert color="red" data-testid="contracts-load-error">
+        Failed to load contracts. Please refresh.
+      </Alert>
+    )
+  }
+
+  const contracts = contractsQuery.data.items
+
+  return (
+    <Stack gap="lg" data-testid="contract-manager">
+      <Group justify="space-between" align="center">
+        <Text fw={500}>Energy Contracts</Text>
+        <Button onClick={() => setShowCreateForm(true)} data-testid="contract-new-button">
+          New Contract
+        </Button>
+      </Group>
+
+      <ContractTable
+        contracts={contracts}
+        onActivate={handleActivate}
+        onAddVersion={(c) => setAddVersionContract(c)}
+        onViewHistory={(c) => setHistoryContract(c)}
+        activatingId={activatingId}
+      />
+
+      {/* Create new contract */}
+      {showCreateForm && (
+        <ContractForm
+          onClose={() => setShowCreateForm(false)}
+          onSaved={() => setShowCreateForm(false)}
+        />
+      )}
+
+      {/* Add version to existing contract */}
+      {addVersionContract && (
+        <ContractForm
+          contractId={addVersionContract.id}
+          defaultKind={addVersionContract.kind}
+          onClose={() => setAddVersionContract(null)}
+          onSaved={() => setAddVersionContract(null)}
+        />
+      )}
+
+      {/* Version history modal */}
+      {historyContract && (
+        <VersionHistoryModal
+          contractId={historyContract.id}
+          contractName={historyContract.name}
+          onClose={() => setHistoryContract(null)}
+        />
+      )}
+    </Stack>
+  )
+}
@@ -0,0 +1,214 @@
+/**
+ * Tests for CostView component.
+ *
+ * Coverage:
+ * 1. Loading state.
+ * 2. Empty state.
+ * 3. Renders costs table with data.
+ * 4. Shows summary values.
+ * 5. Recompute button triggers confirmation modal and then recompute call.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { renderWithProviders } from '../test-utils'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: vi.fn(),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const COST_PERIOD = {
+  period_start: '2026-06-22T10:00:00Z',
+  d1_kwh: 0.1,
+  d2_kwh: 0.2,
+  r1_kwh: 0.0,
+  r2_kwh: 0.05,
+  import_cost: 0.044,
+  export_revenue: 0.005,
+  net_cost: 0.039,
+  currency: 'EUR',
+  degraded: false,
+  contract_version_id: 1,
+}
+
+const SUMMARY = {
+  currency: 'EUR',
+  metered_import: 10.5,
+  metered_export: 2.3,
+  metered_net: 8.2,
+  fixed_costs: 5.0,
+  credits: 50.0,
+  total_payable: 12.5,
+}
+
+// ---------------------------------------------------------------------------
+// Import component
+// ---------------------------------------------------------------------------
+
+import { CostView } from './CostView'
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('CostView', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders loading state initially', () => {
+    mockGet.mockImplementation(() => new Promise(() => {}))
+
+    renderWithProviders(<CostView />)
+
+    expect(screen.getByTestId('costs-loading')).toBeInTheDocument()
+  })
+
+  it('renders empty state when no cost periods available', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/costs') {
+        return Promise.resolve({ data: { items: [], total: 0 } })
+      }
+      if (path === '/api/energy/costs/summary') {
+        return Promise.resolve({ data: SUMMARY })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<CostView />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('costs-empty')).toBeInTheDocument()
+    })
+  })
+
+  it('renders costs table when data is available', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/costs') {
+        return Promise.resolve({ data: { items: [COST_PERIOD], total: 1 } })
+      }
+      if (path === '/api/energy/costs/summary') {
+        return Promise.resolve({ data: SUMMARY })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<CostView />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('costs-table')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('cost-row-0')).toBeInTheDocument()
+  })
+
+  it('shows summary values correctly', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/costs') {
+        return Promise.resolve({ data: { items: [], total: 0 } })
+      }
+      if (path === '/api/energy/costs/summary') {
+        return Promise.resolve({ data: SUMMARY })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<CostView />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('summary-import')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('summary-import')).toHaveTextContent('10.500')
+    expect(screen.getByTestId('summary-export')).toHaveTextContent('2.300')
+    expect(screen.getByTestId('summary-total')).toHaveTextContent('12.50')
+  })
+
+  it('shows recompute confirmation modal on button click', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/costs') {
+        return Promise.resolve({ data: { items: [], total: 0 } })
+      }
+      if (path === '/api/energy/costs/summary') {
+        return Promise.resolve({ data: SUMMARY })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(<CostView />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('cost-recompute-button')).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId('cost-recompute-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('recompute-confirm-modal')).toBeInTheDocument()
+    })
+  })
+
+  it('calls recompute mutation when confirmed', async () => {
+    const user = userEvent.setup()
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/energy/costs') {
+        return Promise.resolve({ data: { items: [], total: 0 } })
+      }
+      if (path === '/api/energy/costs/summary') {
+        return Promise.resolve({ data: SUMMARY })
+      }
+      return Promise.resolve({ data: null })
+    })
+    mockPost.mockResolvedValue({ data: { recomputed: 0 } })
+
+    renderWithProviders(<CostView />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('cost-recompute-button')).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId('cost-recompute-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('recompute-confirm')).toBeInTheDocument()
+    })
+
+    await user.click(screen.getByTestId('recompute-confirm'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/energy/costs/recompute',
+        expect.any(Object),
+      )
+    })
+  })
+})
@@ -0,0 +1,403 @@
+/**
+ * CostView — cost trends + detail + summary.
+ *
+ * Features:
+ * - Date range selector: Today / This month / Custom (SegmentedControl + DateInput).
+ * - Recharts AreaChart showing import_cost, export_revenue, net_cost per period.
+ * - Table showing per-15min periods with time, kWh values, costs, degraded badge.
+ * - Summary cards: metered import/export, fixed costs, credits, total payable.
+ * - "Recompute" button with confirmation.
+ * - Loading/error/empty states, degraded period highlighting.
+ *
+ * Recharts imports are isolated to this file only.
+ */
+
+import { useState } from 'react'
+import {
+  Stack,
+  Text,
+  TextInput,
+  Loader,
+  Center,
+  Alert,
+  Table,
+  Group,
+  Badge,
+  ScrollArea,
+  SegmentedControl,
+  Button,
+  Paper,
+  SimpleGrid,
+  Modal,
+  Title,
+} from '@mantine/core'
+import {
+  AreaChart,
+  Area,
+  XAxis,
+  YAxis,
+  CartesianGrid,
+  Tooltip,
+  Legend,
+  ResponsiveContainer,
+} from 'recharts'
+import { useEnergyCosts, useEnergyCostSummary, useRecomputeCosts } from './hooks'
+import { formatLocalTime } from '../utils/datetime'
+
+// ---------------------------------------------------------------------------
+// Cost limit — prevent accidental full-table pulls
+// ---------------------------------------------------------------------------
+
+const COSTS_MAX_LIMIT = 500
+
+// ---------------------------------------------------------------------------
+// Date range helpers
+// ---------------------------------------------------------------------------
+
+function getTodayRange(): { start: string; end: string } {
+  // Use local date boundary so "today" matches what the user sees in the display.
+  const now = new Date()
+  const start = new Date(now.getFullYear(), now.getMonth(), now.getDate())
+  const end = new Date(now.getFullYear(), now.getMonth(), now.getDate() + 1)
+  return { start: start.toISOString(), end: end.toISOString() }
+}
+
+function getThisMonthRange(): { start: string; end: string } {
+  // Use local date boundary so "this month" matches what the user sees in the display.
+  const now = new Date()
+  const start = new Date(now.getFullYear(), now.getMonth(), 1)
+  const end = new Date(now.getFullYear(), now.getMonth() + 1, 1)
+  return { start: start.toISOString(), end: end.toISOString() }
+}
+
+// ---------------------------------------------------------------------------
+// Summary cards
+// ---------------------------------------------------------------------------
+
+interface SummaryCardProps {
+  label: string
+  value: string
+  testId?: string
+}
+
+function SummaryCard({ label, value, testId }: SummaryCardProps) {
+  return (
+    <Paper withBorder p="sm" data-testid={testId}>
+      <Stack gap={4}>
+        <Text size="xs" c="dimmed">
+          {label}
+        </Text>
+        <Text fw={600} size="lg">
+          {value}
+        </Text>
+      </Stack>
+    </Paper>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// CostView — main component
+// ---------------------------------------------------------------------------
+
+type RangePreset = 'today' | 'month' | 'custom'
+
+export function CostView() {
+  const [rangePreset, setRangePreset] = useState<RangePreset>('today')
+  // Date strings in YYYY-MM-DD format for custom range
+  const [customStartStr, setCustomStartStr] = useState('')
+  const [customEndStr, setCustomEndStr] = useState('')
+  const [showRecomputeConfirm, setShowRecomputeConfirm] = useState(false)
+
+  // Compute effective date range
+  const { start, end } = (() => {
+    if (rangePreset === 'today') return getTodayRange()
+    if (rangePreset === 'month') return getThisMonthRange()
+    return {
+      start: customStartStr ? new Date(customStartStr).toISOString() : undefined,
+      end: customEndStr ? new Date(customEndStr).toISOString() : undefined,
+    }
+  })()
+
+  const costsQuery = useEnergyCosts(start, end, COSTS_MAX_LIMIT)
+  const summaryQuery = useEnergyCostSummary(start, end)
+  const recomputeMutation = useRecomputeCosts()
+
+  async function handleRecompute() {
+    setShowRecomputeConfirm(false)
+    await recomputeMutation.mutateAsync({ start, end })
+  }
+
+  // ---------------------------------------------------------------------------
+  // Render
+  // ---------------------------------------------------------------------------
+
+  const currency = costsQuery.data?.items[0]?.currency ?? summaryQuery.data?.currency ?? 'EUR'
+
+  return (
+    <Stack gap="lg" data-testid="cost-view">
+      {/* Date range selector */}
+      <Group align="flex-start" gap="md" wrap="wrap">
+        <Stack gap="xs">
+          <Text size="sm" fw={500}>
+            Date range
+          </Text>
+          <SegmentedControl
+            value={rangePreset}
+            onChange={(v) => setRangePreset(v as RangePreset)}
+            data={[
+              { label: 'Today', value: 'today' },
+              { label: 'This month', value: 'month' },
+              { label: 'Custom', value: 'custom' },
+            ]}
+            data-testid="cost-range-control"
+          />
+        </Stack>
+
+        {rangePreset === 'custom' && (
+          <Group gap="sm" align="flex-end">
+            <TextInput
+              label="From"
+              type="date"
+              value={customStartStr}
+              onChange={(e) => setCustomStartStr(e.currentTarget.value)}
+              data-testid="cost-custom-start"
+            />
+            <TextInput
+              label="To"
+              type="date"
+              value={customEndStr}
+              onChange={(e) => setCustomEndStr(e.currentTarget.value)}
+              data-testid="cost-custom-end"
+            />
+          </Group>
+        )}
+
+        <Group gap="sm" style={{ marginLeft: 'auto' }} align="flex-end">
+          <Button
+            variant="outline"
+            color="orange"
+            size="sm"
+            onClick={() => setShowRecomputeConfirm(true)}
+            loading={recomputeMutation.isPending}
+            data-testid="cost-recompute-button"
+          >
+            Recompute
+          </Button>
+        </Group>
+      </Group>
+
+      {/* Summary cards */}
+      {summaryQuery.isLoading && (
+        <Center>
+          <Loader size="sm" />
+        </Center>
+      )}
+
+      {summaryQuery.isError && (
+        <Alert color="red" data-testid="summary-error">
+          Failed to load cost summary.
+        </Alert>
+      )}
+
+      {summaryQuery.data && (
+        <Stack gap="xs">
+          <Title order={6} c="dimmed">
+            Summary
+          </Title>
+          <SimpleGrid cols={{ base: 2, sm: 3 }} spacing="sm" data-testid="cost-summary">
+            <SummaryCard
+              label="Import (kWh)"
+              value={summaryQuery.data.metered_import.toFixed(3)}
+              testId="summary-import"
+            />
+            <SummaryCard
+              label="Export (kWh)"
+              value={summaryQuery.data.metered_export.toFixed(3)}
+              testId="summary-export"
+            />
+            <SummaryCard
+              label={`Fixed costs (${currency})`}
+              value={summaryQuery.data.fixed_costs.toFixed(2)}
+              testId="summary-fixed"
+            />
+            <SummaryCard
+              label={`Credits (${currency})`}
+              value={summaryQuery.data.credits.toFixed(2)}
+              testId="summary-credits"
+            />
+            <SummaryCard
+              label={`Total payable (${currency})`}
+              value={summaryQuery.data.total_payable.toFixed(2)}
+              testId="summary-total"
+            />
+          </SimpleGrid>
+        </Stack>
+      )}
+
+      {/* Cost chart */}
+      {costsQuery.isLoading && (
+        <Center py="xl" data-testid="costs-loading">
+          <Loader />
+        </Center>
+      )}
+
+      {costsQuery.isError && (
+        <Alert color="red" data-testid="costs-error">
+          Failed to load cost periods. Please refresh.
+        </Alert>
+      )}
+
+      {costsQuery.data && costsQuery.data.items.length === 0 && (
+        <Alert color="gray" data-testid="costs-empty">
+          No cost data available for the selected period.
+        </Alert>
+      )}
+
+      {costsQuery.data && costsQuery.data.items.length > 0 && (
+        <>
+          {/* Area chart */}
+          <Stack gap="xs" data-testid="cost-chart">
+            <Title order={6} c="dimmed">
+              Cost trends ({currency})
+            </Title>
+            <ResponsiveContainer width="100%" height={220}>
+              <AreaChart
+                data={costsQuery.data.items.map((item) => ({
+                  time: formatLocalTime(item.period_start),
+                  import_cost: item.import_cost,
+                  export_revenue: item.export_revenue,
+                  net_cost: item.net_cost,
+                }))}
+                margin={{ top: 4, right: 16, left: 0, bottom: 4 }}
+              >
+                <CartesianGrid strokeDasharray="3 3" />
+                <XAxis dataKey="time" tick={{ fontSize: 10 }} interval="preserveStartEnd" />
+                <YAxis tick={{ fontSize: 10 }} tickFormatter={(v: number) => v.toFixed(2)} />
+                <Tooltip
+                  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                  formatter={(val: any) =>
+                    [`${typeof val === 'number' ? val.toFixed(4) : String(val)} ${currency}`, undefined]
+                  }
+                />
+                <Legend />
+                <Area
+                  type="monotone"
+                  dataKey="import_cost"
+                  stroke="#2196f3"
+                  fill="#bbdefb"
+                  name="Import cost"
+                  dot={false}
+                />
+                <Area
+                  type="monotone"
+                  dataKey="export_revenue"
+                  stroke="#4caf50"
+                  fill="#c8e6c9"
+                  name="Export revenue"
+                  dot={false}
+                />
+                <Area
+                  type="monotone"
+                  dataKey="net_cost"
+                  stroke="#ff9800"
+                  fill="#ffe0b2"
+                  name="Net cost"
+                  dot={false}
+                />
+              </AreaChart>
+            </ResponsiveContainer>
+          </Stack>
+
+          {/* Detail table */}
+          <Stack gap="xs">
+            <Title order={6} c="dimmed">
+              Period detail
+            </Title>
+            <ScrollArea>
+              <Table
+                striped
+                highlightOnHover
+                withTableBorder
+                withColumnBorders
+                style={{ fontSize: 12 }}
+                data-testid="costs-table"
+              >
+                <Table.Thead>
+                  <Table.Tr>
+                    <Table.Th>Time</Table.Th>
+                    <Table.Th>Import kWh</Table.Th>
+                    <Table.Th>Export kWh</Table.Th>
+                    <Table.Th>Import cost</Table.Th>
+                    <Table.Th>Export rev.</Table.Th>
+                    <Table.Th>Net cost</Table.Th>
+                    <Table.Th></Table.Th>
+                  </Table.Tr>
+                </Table.Thead>
+                <Table.Tbody>
+                  {costsQuery.data.items.map((item, idx) => (
+                    <Table.Tr
+                      key={idx}
+                      style={item.degraded ? { opacity: 0.6 } : undefined}
+                      data-testid={`cost-row-${idx}`}
+                    >
+                      <Table.Td>
+                        <Text size="xs">
+                          {formatLocalTime(item.period_start)}
+                        </Text>
+                      </Table.Td>
+                      <Table.Td>{(item.d1_kwh + item.d2_kwh).toFixed(3)}</Table.Td>
+                      <Table.Td>{(item.r1_kwh + item.r2_kwh).toFixed(3)}</Table.Td>
+                      <Table.Td>{item.import_cost.toFixed(4)}</Table.Td>
+                      <Table.Td>{item.export_revenue.toFixed(4)}</Table.Td>
+                      <Table.Td>{item.net_cost.toFixed(4)}</Table.Td>
+                      <Table.Td>
+                        {item.degraded && (
+                          <Badge color="orange" size="xs" data-testid={`cost-degraded-${idx}`}>
+                            degraded
+                          </Badge>
+                        )}
+                      </Table.Td>
+                    </Table.Tr>
+                  ))}
+                </Table.Tbody>
+              </Table>
+            </ScrollArea>
+          </Stack>
+        </>
+      )}
+
+      {/* Recompute confirmation modal */}
+      {showRecomputeConfirm && (
+        <Modal
+          opened
+          onClose={() => setShowRecomputeConfirm(false)}
+          title="Recompute costs?"
+          size="sm"
+          data-testid="recompute-confirm-modal"
+        >
+          <Stack gap="md">
+            <Text size="sm">
+              This will recompute all cost periods for the selected date range. Continue?
+            </Text>
+            <Group justify="flex-end" gap="sm">
+              <Button
+                variant="default"
+                onClick={() => setShowRecomputeConfirm(false)}
+                data-testid="recompute-cancel"
+              >
+                Cancel
+              </Button>
+              <Button
+                color="orange"
+                onClick={handleRecompute}
+                data-testid="recompute-confirm"
+              >
+                Recompute
+              </Button>
+            </Group>
+          </Stack>
+        </Modal>
+      )}
+    </Stack>
+  )
+}
@@ -0,0 +1,241 @@
+/**
+ * Tests for energy/DeviceForm.tsx
+ *
+ * Coverage:
+ * 1. Renders empty form in create mode (title "New Device").
+ * 2. Renders pre-filled form in edit mode (title "Edit Device"), shows UUID.
+ * 3. Validation: missing friendly_name shows error.
+ * 4. Profile dropdown loads options from GET /api/modbus/profiles.
+ * 5. Submit in create mode calls POST /api/modbus/devices.
+ * 6. Submit in edit mode calls PATCH /api/modbus/devices/{uuid}.
+ * 7. Cancel button invokes onClose without submitting.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor, fireEvent } from '@testing-library/react'
+import { renderWithProviders } from '../test-utils'
+import { DeviceForm } from './DeviceForm'
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const DEVICE = {
+  uuid: 'abc-123',
+  friendly_name: 'SDM120 Main',
+  transport: 'tcp',
+  host: '192.168.1.100',
+  port: 502,
+  unit_id: 1,
+  profile: 'sdm120',
+  poll_interval_s: 5,
+  enabled: true,
+  last_poll_at: null,
+  last_poll_ok: null,
+  created_at: '2026-06-01T00:00:00Z',
+  updated_at: '2026-06-01T00:00:00Z',
+}
+
+const PROFILES_RESP = {
+  profiles: [{ name: 'sdm120', description: 'Eastron SDM120 single-phase energy meter' }],
+}
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+const mockPatch = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: (...args: unknown[]) => mockPatch(...args),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+function setupProfilesMock() {
+  mockGet.mockImplementation((path: string) => {
+    if (path === '/api/modbus/profiles') {
+      return Promise.resolve({ data: PROFILES_RESP })
+    }
+    // modbus-devices for invalidation
+    return Promise.resolve({ data: { items: [], total: 0 } })
+  })
+}
+
+function renderCreateForm(onClose = vi.fn(), onSaved = vi.fn()) {
+  return renderWithProviders(<DeviceForm onClose={onClose} onSaved={onSaved} />, {
+    initialPath: '/',
+  })
+}
+
+function renderEditForm(onClose = vi.fn(), onSaved = vi.fn()) {
+  return renderWithProviders(<DeviceForm device={DEVICE} onClose={onClose} onSaved={onSaved} />, {
+    initialPath: '/',
+  })
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('DeviceForm — create mode', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    setupProfilesMock()
+  })
+
+  it('renders with title "New Device" and empty friendly-name input', async () => {
+    renderCreateForm()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('device-form-modal')).toBeInTheDocument()
+    })
+
+    // Modal title
+    expect(screen.getByText('New Device')).toBeInTheDocument()
+
+    // UUID display should NOT be present in create mode
+    expect(screen.queryByTestId('device-uuid-display')).not.toBeInTheDocument()
+  })
+
+  it('loads profile options from GET /api/modbus/profiles', async () => {
+    renderCreateForm()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('device-form')).toBeInTheDocument()
+    })
+
+    // Profile select should be rendered
+    expect(screen.getByTestId('device-profile')).toBeInTheDocument()
+    expect(mockGet).toHaveBeenCalledWith('/api/modbus/profiles')
+  })
+
+  it('shows validation error when friendly name is empty', async () => {
+    renderCreateForm()
+
+    await waitFor(() => expect(screen.getByTestId('device-form')).toBeInTheDocument())
+
+    fireEvent.submit(screen.getByTestId('device-form'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('device-form-error')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('device-form-error').textContent).toContain('Friendly name')
+  })
+
+  it('submit calls POST /api/modbus/devices with correct body (profile auto-selected)', async () => {
+    mockPost.mockResolvedValue({ data: DEVICE })
+    const onSaved = vi.fn()
+    renderCreateForm(vi.fn(), onSaved)
+
+    // Wait for profiles to load; sdm120 is auto-selected as first profile.
+    await waitFor(() => expect(screen.getByTestId('device-form')).toBeInTheDocument())
+
+    // Fill form (profile auto-selected to 'sdm120')
+    fireEvent.change(screen.getByTestId('device-friendly-name'), {
+      target: { value: 'My Meter' },
+    })
+    fireEvent.change(screen.getByTestId('device-host'), {
+      target: { value: '10.0.0.1' },
+    })
+
+    fireEvent.submit(screen.getByTestId('device-form'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/modbus/devices',
+        expect.objectContaining({
+          body: expect.objectContaining({
+            friendly_name: 'My Meter',
+            host: '10.0.0.1',
+            transport: 'tcp',
+            profile: 'sdm120',
+          }),
+        }),
+      )
+    })
+  })
+
+  it('cancel calls onClose without POST', async () => {
+    const onClose = vi.fn()
+    renderCreateForm(onClose)
+
+    await waitFor(() => expect(screen.getByTestId('device-form-cancel')).toBeInTheDocument())
+
+    fireEvent.click(screen.getByTestId('device-form-cancel'))
+
+    expect(onClose).toHaveBeenCalledOnce()
+    expect(mockPost).not.toHaveBeenCalled()
+  })
+})
+
+describe('DeviceForm — edit mode', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    setupProfilesMock()
+  })
+
+  it('renders with title "Edit Device" and pre-filled friendly-name', async () => {
+    renderEditForm()
+
+    // Wait for modal to appear
+    await waitFor(() => {
+      expect(screen.getByTestId('device-form-modal')).toBeInTheDocument()
+    })
+
+    expect(screen.getByText('Edit Device')).toBeInTheDocument()
+
+    // Wait for form to appear (profiles must load first)
+    await waitFor(() => {
+      expect(screen.getByTestId('device-form')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('device-uuid-display').textContent).toContain('abc-123')
+
+    // Friendly name input should be pre-filled
+    const input = screen.getByTestId('device-friendly-name') as HTMLInputElement
+    expect(input.value).toBe('SDM120 Main')
+  })
+
+  it('submit calls PATCH /api/modbus/devices/{uuid}', async () => {
+    mockPatch.mockResolvedValue({ data: DEVICE })
+    renderEditForm()
+
+    // Wait for profiles to load so the form is visible
+    await waitFor(() => expect(screen.getByTestId('device-form')).toBeInTheDocument())
+
+    fireEvent.change(screen.getByTestId('device-friendly-name'), {
+      target: { value: 'SDM120 Updated' },
+    })
+
+    fireEvent.submit(screen.getByTestId('device-form'))
+
+    await waitFor(() => {
+      expect(mockPatch).toHaveBeenCalledWith('/api/modbus/devices/{uuid}', {
+        params: { path: { uuid: 'abc-123' } },
+        body: expect.objectContaining({ friendly_name: 'SDM120 Updated' }),
+      })
+    })
+  })
+})
@@ -0,0 +1,263 @@
+/**
+ * DeviceForm — create / edit a Modbus device.
+ *
+ * Used for both new-device creation (no `device` prop) and editing an
+ * existing device (pass `device` prop with current values).
+ *
+ * Profile list is fetched from GET /api/modbus/profiles and rendered as a
+ * Select dropdown.  All other fields are inline inputs.
+ */
+
+import { useState } from 'react'
+import {
+  Modal,
+  Stack,
+  TextInput,
+  NumberInput,
+  Select,
+  Switch,
+  Button,
+  Group,
+  Alert,
+  Loader,
+  Center,
+  Text,
+} from '@mantine/core'
+import { useProfiles, useCreateDevice, useUpdateDevice } from './hooks'
+import type { ModbusDevice, ModbusDeviceCreate, ModbusDeviceUpdate } from './hooks'
+
+// ---------------------------------------------------------------------------
+// Props
+// ---------------------------------------------------------------------------
+
+interface DeviceFormProps {
+  /** When provided, the form is in edit mode; otherwise create mode. */
+  device?: ModbusDevice
+  onClose: () => void
+  onSaved: () => void
+}
+
+// ---------------------------------------------------------------------------
+// Component
+// ---------------------------------------------------------------------------
+
+export function DeviceForm({ device, onClose, onSaved }: DeviceFormProps) {
+  const isEdit = !!device
+
+  // Form state — initialise from device if editing.
+  const [friendlyName, setFriendlyName] = useState(device?.friendly_name ?? '')
+  const [host, setHost] = useState(device?.host ?? '')
+  const [port, setPort] = useState<number | string>(device?.port ?? 502)
+  const [unitId, setUnitId] = useState<number | string>(device?.unit_id ?? 1)
+  const [profile, setProfile] = useState<string | null>(device?.profile ?? null)
+  const [pollIntervalS, setPollIntervalS] = useState<number | string>(device?.poll_interval_s ?? 5)
+  const [enabled, setEnabled] = useState(device?.enabled ?? true)
+  const [error, setError] = useState<string | null>(null)
+
+  const profilesQuery = useProfiles()
+  const createMutation = useCreateDevice()
+  const updateMutation = useUpdateDevice()
+
+  const isBusy = createMutation.isPending || updateMutation.isPending
+
+  // Build select options from profiles response.
+  const profileOptions =
+    profilesQuery.data?.profiles.map((p) => ({
+      value: p.name,
+      label: `${p.name} — ${p.description}`,
+    })) ?? []
+
+  // In create mode, if no explicit selection has been made and profiles are loaded,
+  // derive a default from the first available profile.  We avoid useEffect+setState
+  // (causes cascading renders) by computing the effective value here instead.
+  const effectiveProfile: string | null =
+    profile !== null
+      ? profile
+      : !isEdit && profileOptions.length > 0
+        ? profileOptions[0].value
+        : null
+
+  // ---------------------------------------------------------------------------
+  // Validation
+  // ---------------------------------------------------------------------------
+
+  function validate(): string | null {
+    if (!friendlyName.trim()) return 'Friendly name is required.'
+    if (!host.trim()) return 'Host is required.'
+    const portNum = Number(port)
+    if (!Number.isInteger(portNum) || portNum < 1 || portNum > 65535)
+      return 'Port must be an integer between 1 and 65535.'
+    const unitNum = Number(unitId)
+    if (!Number.isInteger(unitNum) || unitNum < 1 || unitNum > 247)
+      return 'Unit ID must be an integer between 1 and 247.'
+    if (!effectiveProfile) return 'Profile is required.'
+    const pollNum = Number(pollIntervalS)
+    if (!Number.isInteger(pollNum) || pollNum < 1)
+      return 'Poll interval must be a positive integer (seconds).'
+    return null
+  }
+
+  // ---------------------------------------------------------------------------
+  // Submit
+  // ---------------------------------------------------------------------------
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setError(null)
+
+    const validationError = validate()
+    if (validationError) {
+      setError(validationError)
+      return
+    }
+
+    try {
+      if (isEdit && device) {
+        const body: ModbusDeviceUpdate = {
+          friendly_name: friendlyName.trim(),
+          host: host.trim(),
+          port: Number(port),
+          unit_id: Number(unitId),
+          profile: effectiveProfile!,
+          poll_interval_s: Number(pollIntervalS),
+          enabled,
+        }
+        await updateMutation.mutateAsync({ uuid: device.uuid, body })
+      } else {
+        const body: ModbusDeviceCreate = {
+          friendly_name: friendlyName.trim(),
+          transport: 'tcp',
+          host: host.trim(),
+          port: Number(port),
+          unit_id: Number(unitId),
+          profile: effectiveProfile!,
+          poll_interval_s: Number(pollIntervalS),
+          enabled,
+        }
+        await createMutation.mutateAsync(body)
+      }
+      onSaved()
+      onClose()
+    } catch {
+      setError('Failed to save device. Please try again.')
+    }
+  }
+
+  // ---------------------------------------------------------------------------
+  // Render
+  // ---------------------------------------------------------------------------
+
+  return (
+    <Modal
+      opened
+      onClose={onClose}
+      title={isEdit ? 'Edit Device' : 'New Device'}
+      size="md"
+      data-testid="device-form-modal"
+    >
+      {profilesQuery.isLoading && (
+        <Center py="md">
+          <Loader size="sm" />
+        </Center>
+      )}
+
+      {profilesQuery.isError && (
+        <Alert color="red" mb="sm" data-testid="profiles-load-error">
+          Failed to load profiles. Cannot create device.
+        </Alert>
+      )}
+
+      {!profilesQuery.isLoading && (
+        <form onSubmit={handleSubmit} data-testid="device-form">
+          <Stack gap="sm">
+            {isEdit && (
+              <Text size="xs" c="dimmed" data-testid="device-uuid-display">
+                UUID: {device!.uuid}
+              </Text>
+            )}
+
+            <TextInput
+              label="Friendly name"
+              required
+              value={friendlyName}
+              onChange={(e) => setFriendlyName(e.currentTarget.value)}
+              data-testid="device-friendly-name"
+            />
+
+            <TextInput
+              label="Host"
+              description="Gateway IP address"
+              required
+              value={host}
+              onChange={(e) => setHost(e.currentTarget.value)}
+              data-testid="device-host"
+            />
+
+            <NumberInput
+              label="Port"
+              required
+              min={1}
+              max={65535}
+              value={port}
+              onChange={(val) => setPort(val)}
+              data-testid="device-port"
+            />
+
+            <NumberInput
+              label="Unit ID"
+              description="Modbus slave address (Meter ID on device panel)"
+              required
+              min={1}
+              max={247}
+              value={unitId}
+              onChange={(val) => setUnitId(val)}
+              data-testid="device-unit-id"
+            />
+
+            <Select
+              label="Profile"
+              description="YAML device profile"
+              required
+              data={profileOptions}
+              value={effectiveProfile}
+              onChange={setProfile}
+              data-testid="device-profile"
+            />
+
+            <NumberInput
+              label="Poll interval (seconds)"
+              required
+              min={1}
+              value={pollIntervalS}
+              onChange={(val) => setPollIntervalS(val)}
+              data-testid="device-poll-interval"
+            />
+
+            <Switch
+              label="Enabled"
+              description="Whether this device is polled"
+              checked={enabled}
+              onChange={(e) => setEnabled(e.currentTarget.checked)}
+              data-testid="device-enabled"
+            />
+
+            {error && (
+              <Alert color="red" data-testid="device-form-error">
+                {error}
+              </Alert>
+            )}
+
+            <Group justify="flex-end" gap="sm">
+              <Button variant="default" onClick={onClose} data-testid="device-form-cancel">
+                Cancel
+              </Button>
+              <Button type="submit" loading={isBusy} data-testid="device-form-submit">
+                {isEdit ? 'Save' : 'Create'}
+              </Button>
+            </Group>
+          </Stack>
+        </form>
+      )}
+    </Modal>
+  )
+}
@@ -0,0 +1,82 @@
+/**
+ * Tests for DsmrPanel — latest parsed DSMR telegram view.
+ *
+ * Coverage:
+ * 1. Loading state.
+ * 2. Empty state (found=false) with a helpful hint.
+ * 3. Renders the payload as a key/value table; null values shown as "—".
+ * 4. Error state.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import { renderWithProviders } from '../test-utils'
+
+const mockGet = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: vi.fn(),
+    PATCH: vi.fn(),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+import { DsmrPanel } from './DsmrPanel'
+
+describe('DsmrPanel', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders loading state initially', () => {
+    mockGet.mockImplementation(() => new Promise(() => {}))
+    renderWithProviders(<DsmrPanel />)
+    expect(screen.getByTestId('dsmr-loading')).toBeInTheDocument()
+  })
+
+  it('shows an empty hint when no DSMR data has been ingested', async () => {
+    mockGet.mockResolvedValue({ data: { found: false, recorded_at: null, payload: null } })
+    renderWithProviders(<DsmrPanel />)
+    await waitFor(() => expect(screen.getByTestId('dsmr-empty')).toBeInTheDocument())
+    expect(screen.queryByTestId('dsmr-table')).not.toBeInTheDocument()
+  })
+
+  it('renders the latest telegram as a key/value table; null shown as dash', async () => {
+    mockGet.mockResolvedValue({
+      data: {
+        found: true,
+        recorded_at: '2026-06-23T12:16:00Z',
+        payload: {
+          electricity_delivered_1: '20915.154',
+          phase_voltage_l2: null,
+        },
+      },
+    })
+    renderWithProviders(<DsmrPanel />)
+
+    await waitFor(() => expect(screen.getByTestId('dsmr-table')).toBeInTheDocument())
+
+    // Field rows present (keys are sorted).
+    expect(screen.getByTestId('dsmr-row-electricity_delivered_1')).toHaveTextContent('20915.154')
+    // Null phase value rendered as an em dash, not omitted.
+    expect(screen.getByTestId('dsmr-row-phase_voltage_l2')).toHaveTextContent('—')
+    expect(screen.getByTestId('dsmr-recorded-at')).toBeInTheDocument()
+  })
+
+  it('renders an error state when the request fails', async () => {
+    mockGet.mockRejectedValue(new Error('network down'))
+    renderWithProviders(<DsmrPanel />)
+    await waitFor(() => expect(screen.getByTestId('dsmr-error')).toBeInTheDocument())
+  })
+})
@@ -0,0 +1,154 @@
+/**
+ * DsmrPanel — shows the latest parsed DSMR telegram (the source of our metering data).
+ *
+ * This is the "ground truth" view: it fetches GET /api/energy/dsmr/latest and
+ * renders the full parsed frame as a key/value table, so you can confirm at a
+ * glance whether DSMR ingest is actually landing data (without reading the DB).
+ *
+ * - Auto-refresh toggle (default on) so new telegrams appear without a manual reload.
+ * - Loading / error / empty states; "empty" explains the likely cause.
+ * - Null phase values are shown as "—" (kept verbatim in the payload).
+ */
+
+import { useState } from 'react'
+import {
+  Stack,
+  Group,
+  Text,
+  Loader,
+  Center,
+  Alert,
+  Paper,
+  Table,
+  ScrollArea,
+  Switch,
+  Divider,
+  Badge,
+} from '@mantine/core'
+import { useDsmrLatest } from './hooks'
+import { formatLocalDateTime } from '../utils/datetime'
+
+/** Default auto-refresh interval (ms) — DSMR ingest stores ~one row per 10 s. */
+const AUTO_REFRESH_INTERVAL_MS = 10_000
+
+function formatValue(value: unknown): string {
+  if (value === null || value === undefined) return '—'
+  if (typeof value === 'object') return JSON.stringify(value)
+  return String(value)
+}
+
+export function DsmrPanel() {
+  const [autoRefresh, setAutoRefresh] = useState(true)
+  const latestQuery = useDsmrLatest(
+    autoRefresh ? { refetchIntervalMs: AUTO_REFRESH_INTERVAL_MS } : undefined,
+  )
+
+  return (
+    <Stack gap="md" data-testid="dsmr-panel">
+      <Group justify="space-between" align="center">
+        <div>
+          <Text fw={600}>Latest DSMR reading</Text>
+          <Text size="xs" c="dimmed">
+            The most recent parsed telegram persisted to <code>dsmr_reading</code>.
+          </Text>
+        </div>
+        <Switch
+          label="Auto-refresh"
+          checked={autoRefresh}
+          onChange={(e) => setAutoRefresh(e.currentTarget.checked)}
+          size="sm"
+          data-testid="dsmr-auto-refresh-switch"
+        />
+      </Group>
+
+      <Divider />
+
+      <DsmrContent
+        isLoading={latestQuery.isLoading}
+        isError={latestQuery.isError}
+        data={latestQuery.data}
+      />
+    </Stack>
+  )
+}
+
+interface DsmrContentProps {
+  isLoading: boolean
+  isError: boolean
+  data:
+    | { found: boolean; recorded_at?: string | null; payload?: Record<string, unknown> | null }
+    | undefined
+}
+
+function DsmrContent({ isLoading, isError, data }: DsmrContentProps) {
+  if (isLoading) {
+    return (
+      <Center py="xl" data-testid="dsmr-loading">
+        <Loader />
+      </Center>
+    )
+  }
+
+  if (isError || !data) {
+    return (
+      <Alert color="red" data-testid="dsmr-error">
+        Failed to load the latest DSMR reading.
+      </Alert>
+    )
+  }
+
+  if (!data.found || !data.payload) {
+    return (
+      <Alert color="gray" data-testid="dsmr-empty">
+        No DSMR data yet. Enable <strong>DSMR ingest</strong> in Config, make sure MQTT
+        is connected, and confirm the DSMR Reader is publishing to the configured topic
+        (default <code>dsmr/json</code>). Rows are stored about once every 10 seconds.
+      </Alert>
+    )
+  }
+
+  const payload = data.payload
+  const keys = Object.keys(payload).sort()
+
+  return (
+    <Stack gap="sm" data-testid="dsmr-data">
+      <Group gap="xs">
+        <Badge color="teal" variant="light">
+          {keys.length} fields
+        </Badge>
+        {data.recorded_at && (
+          <Text size="sm" c="dimmed" data-testid="dsmr-recorded-at">
+            recorded at {formatLocalDateTime(data.recorded_at)}
+          </Text>
+        )}
+      </Group>
+
+      <Paper withBorder>
+        <ScrollArea.Autosize mah={480}>
+          <Table striped highlightOnHover withColumnBorders data-testid="dsmr-table">
+            <Table.Thead>
+              <Table.Tr>
+                <Table.Th>Field</Table.Th>
+                <Table.Th>Value</Table.Th>
+              </Table.Tr>
+            </Table.Thead>
+            <Table.Tbody>
+              {keys.map((key) => (
+                <Table.Tr key={key} data-testid={`dsmr-row-${key}`}>
+                  <Table.Td>
+                    <Text size="sm" ff="monospace">
+                      {key}
+                    </Text>
+                  </Table.Td>
+                  <Table.Td>
+                    <Text size="sm">{formatValue(payload[key])}</Text>
+                  </Table.Td>
+                </Table.Tr>
+              ))}
+            </Table.Tbody>
+          </Table>
+        </ScrollArea.Autosize>
+      </Paper>
+    </Stack>
+  )
+}
@@ -0,0 +1,375 @@
+/**
+ * Tests for energy/EnergyCharts.tsx
+ *
+ * Coverage:
+ * 1. Renders chart title with device name.
+ * 2. Shows loading state while readings/metrics are loading.
+ * 3. Shows error state when either query fails.
+ * 4. Shows empty state when no readings are in the time window.
+ * 5. Renders chart container when data is available.
+ * 6. Tolerates missing keys in payload (no crash when key absent).
+ * 7. Time-range segmented control is rendered.
+ *
+ * NOTE: Recharts itself is NOT mocked — we let it render (jsdom-compatible
+ * rendering), but we only assert on data-testid wrappers, not Recharts internals.
+ * Recharts SVG rendering may produce warnings in jsdom; these are expected and
+ * benign (jsdom lacks ResizeObserver / SVG layout).
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import { renderWithProviders } from '../test-utils'
+import { EnergyCharts } from './EnergyCharts'
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const UUID = 'device-uuid-test'
+const DEVICE_NAME = 'SDM120 Main'
+
+const METRICS_RESP = {
+  profile: 'sdm120',
+  metrics: [
+    { key: 'voltage', label: 'Voltage', unit: 'V', device_class: 'voltage' },
+    { key: 'current', label: 'Current', unit: 'A', device_class: 'current' },
+  ],
+}
+
+const READING = {
+  recorded_at: '2026-06-22T10:00:00Z',
+  payload: { voltage: 230.2, current: 1.3 },
+}
+
+const READINGS_RESP = {
+  items: [READING],
+}
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: vi.fn(),
+    PATCH: vi.fn(),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+function setupDefaultMocks() {
+  mockGet.mockImplementation((path: string) => {
+    if (path === '/api/modbus/devices/{uuid}/metrics') {
+      return Promise.resolve({ data: METRICS_RESP })
+    }
+    if (path === '/api/modbus/devices/{uuid}/readings') {
+      return Promise.resolve({ data: READINGS_RESP })
+    }
+    return Promise.resolve({ data: null })
+  })
+}
+
+function renderChart() {
+  return renderWithProviders(
+    <EnergyCharts uuid={UUID} deviceName={DEVICE_NAME} />,
+    { initialPath: '/energy' },
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('EnergyCharts — rendering', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    setupDefaultMocks()
+  })
+
+  it('renders chart title with device name', async () => {
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-title-${UUID}`)).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId(`energy-charts-title-${UUID}`).textContent).toBe(DEVICE_NAME)
+  })
+
+  it('renders time-range segmented control', async () => {
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-preset-${UUID}`)).toBeInTheDocument()
+    })
+  })
+
+  it('shows loading state while data is being fetched', () => {
+    // Never resolve
+    mockGet.mockReturnValue(new Promise(() => {}))
+    renderChart()
+
+    expect(screen.getByTestId(`energy-charts-loading-${UUID}`)).toBeInTheDocument()
+  })
+
+  it('shows error state when readings query fails', async () => {
+    mockGet.mockRejectedValue(new Error('Network error'))
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-error-${UUID}`)).toBeInTheDocument()
+    })
+  })
+
+  it('shows empty state when no readings in time window', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        return Promise.resolve({ data: { items: [] } })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-empty-${UUID}`)).toBeInTheDocument()
+    })
+  })
+
+  it('renders chart container when data is available', async () => {
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-chart-${UUID}`)).toBeInTheDocument()
+    })
+  })
+})
+
+describe('EnergyCharts — truncation notice', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('shows truncation notice when readings count equals the limit cap (1000)', async () => {
+    // Build exactly 1000 synthetic readings to trigger the truncation hint.
+    const truncatedItems = Array.from({ length: 1000 }, (_, i) => ({
+      recorded_at: new Date(Date.now() - (999 - i) * 5000).toISOString(),
+      payload: { voltage: 230 + i * 0.01 },
+    }))
+
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        return Promise.resolve({ data: { items: truncatedItems } })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderChart()
+
+    await waitFor(() => {
+      expect(
+        screen.getByTestId(`energy-charts-truncated-${UUID}`),
+      ).toBeInTheDocument()
+    })
+  })
+
+  it('does NOT show truncation notice when readings count is below limit', async () => {
+    // Default mock has exactly 1 item — well below 1000.
+    setupDefaultMocks()
+    renderChart()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-chart-${UUID}`)).toBeInTheDocument()
+    })
+
+    expect(screen.queryByTestId(`energy-charts-truncated-${UUID}`)).not.toBeInTheDocument()
+  })
+})
+
+describe('EnergyCharts — payload key tolerance', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('does not crash when payload is missing a metric key', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        // payload is missing 'current' key
+        return Promise.resolve({
+          data: { items: [{ recorded_at: '2026-06-22T10:00:00Z', payload: { voltage: 230.2 } }] },
+        })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    // Should render without throwing
+    expect(() => renderChart()).not.toThrow()
+
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-${UUID}`)).toBeInTheDocument()
+    })
+  })
+
+  it('does not crash when payload is entirely empty', async () => {
+    mockGet.mockImplementation((path: string) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        return Promise.resolve({
+          data: { items: [{ recorded_at: '2026-06-22T10:00:00Z', payload: {} }] },
+        })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    expect(() => renderChart()).not.toThrow()
+
+    // All values null → empty state (no chart) or chart with no data points shown.
+    await waitFor(() => {
+      expect(screen.getByTestId(`energy-charts-${UUID}`)).toBeInTheDocument()
+    })
+  })
+})
+
+// ---------------------------------------------------------------------------
+// Auto-refresh: rolling window (A2 — the core bug fix)
+// ---------------------------------------------------------------------------
+
+describe('EnergyCharts — auto-refresh rolling window', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  afterEach(() => {
+    vi.clearAllMocks()
+  })
+
+  /**
+   * EnergyCharts now passes spanMs (not fixed start/end) to useReadings.
+   * This means each queryFn invocation computes end=now(), giving a rolling
+   * window.  We verify here that:
+   * - The readings GET is called with an `end` param (window is computed).
+   * - Rendering twice (to simulate a second fetch via queryFn being called
+   *   again) results in a second GET with a later `end` value.
+   *
+   * We test this by manually invoking the apiClient.GET mock twice with a
+   * small real-time delay between them, mimicking what happens when
+   * refetchInterval fires and the queryFn re-runs.
+   */
+  it('uses spanMs-based rolling window so each queryFn call gets a fresh end=now()', async () => {
+    const endTimestamps: string[] = []
+
+    mockGet.mockImplementation((path: string, opts: { params?: { query?: { end?: string } } } = {}) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        const end = opts?.params?.query?.end
+        if (end) endTimestamps.push(end)
+        return Promise.resolve({ data: READINGS_RESP })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    // First render: triggers initial fetch (end=now at T0).
+    const t0 = Date.now()
+    renderWithProviders(
+      <EnergyCharts uuid={UUID} deviceName={DEVICE_NAME} />,
+      { initialPath: '/energy' },
+    )
+
+    // Wait for the initial readings GET to fire.
+    await waitFor(() => expect(endTimestamps.length).toBeGreaterThanOrEqual(1))
+
+    // The recorded `end` must not be before the test started.
+    const firstEndMs = new Date(endTimestamps[0]).getTime()
+    expect(firstEndMs).toBeGreaterThanOrEqual(t0)
+
+    // The readings request must include an `end` query param (window is computed, not omitted).
+    expect(endTimestamps[0]).toBeTruthy()
+  })
+
+  it('does not freeze the window on mount — window end advances across separate renders', async () => {
+    // We simulate two independent hook invocations (as if refetch fired).
+    // Since each queryFn call uses new Date(), the end timestamps will advance
+    // naturally with real time.  We just need to verify the concept holds.
+    const endTimestamps: string[] = []
+
+    mockGet.mockImplementation((path: string, opts: { params?: { query?: { end?: string } } } = {}) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        const end = opts?.params?.query?.end
+        if (end) endTimestamps.push(end)
+        return Promise.resolve({ data: READINGS_RESP })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    const { unmount } = renderWithProviders(
+      <EnergyCharts uuid={UUID} deviceName={DEVICE_NAME} />,
+      { initialPath: '/energy' },
+    )
+
+    await waitFor(() => expect(endTimestamps.length).toBeGreaterThanOrEqual(1))
+
+    const firstEnd = new Date(endTimestamps[0]).getTime()
+
+    // Unmount and re-mount to simulate a new queryFn invocation after a tick.
+    unmount()
+    vi.clearAllMocks()
+    endTimestamps.length = 0
+
+    // Small real-time delay to ensure new Date() will be >= first.
+    await new Promise((resolve) => setTimeout(resolve, 5))
+
+    mockGet.mockImplementation((path: string, opts: { params?: { query?: { end?: string } } } = {}) => {
+      if (path === '/api/modbus/devices/{uuid}/metrics') {
+        return Promise.resolve({ data: METRICS_RESP })
+      }
+      if (path === '/api/modbus/devices/{uuid}/readings') {
+        const end = opts?.params?.query?.end
+        if (end) endTimestamps.push(end)
+        return Promise.resolve({ data: READINGS_RESP })
+      }
+      return Promise.resolve({ data: null })
+    })
+
+    renderWithProviders(
+      <EnergyCharts uuid={UUID} deviceName={DEVICE_NAME} />,
+      { initialPath: '/energy' },
+    )
+
+    await waitFor(() => expect(endTimestamps.length).toBeGreaterThanOrEqual(1))
+
+    const secondEnd = new Date(endTimestamps[0]).getTime()
+
+    // The second invocation's end must be >= the first — window is not frozen.
+    expect(secondEnd).toBeGreaterThanOrEqual(firstEnd)
+  })
+})
@@ -0,0 +1,322 @@
+/**
+ * EnergyCharts — self-contained Recharts wrapper for Modbus device trend charts.
+ *
+ * Design decisions (M5 decision 11):
+ * - Recharts is imported ONLY in this file (isolation, easy to swap later).
+ * - The component is fully self-contained: it owns its own data fetching via
+ *   useReadings / useMetrics hooks and renders loading/error/empty states.
+ * - Time-range selection is internal; readings are always fetched with a window
+ *   + limit cap — never a full-table pull.
+ * - Metric labels and units come from GET /metrics; missing keys in payload are
+ *   tolerated (a null data point is emitted so the line simply has a gap).
+ */
+
+// ---------------------------------------------------------------------------
+// Recharts imports — keep ALL recharts imports inside this file.
+// ---------------------------------------------------------------------------
+
+import {
+  LineChart,
+  Line,
+  XAxis,
+  YAxis,
+  CartesianGrid,
+  Tooltip as RechartsTooltip,
+  Legend,
+  ResponsiveContainer,
+} from 'recharts'
+
+import { useState, useMemo } from 'react'
+import {
+  Stack,
+  Group,
+  Text,
+  Loader,
+  Alert,
+  SegmentedControl,
+  Paper,
+  Title,
+  Badge,
+  Box,
+} from '@mantine/core'
+
+import { useReadings, useMetrics } from './hooks'
+import type { MetricInfo, AutoRefreshOptions } from './hooks'
+import { formatMetricValue } from './format'
+import { formatLocalTime, formatLocalDateTime } from '../utils/datetime'
+
+// ---------------------------------------------------------------------------
+// Constants
+// ---------------------------------------------------------------------------
+
+/** Must match the limit passed to useReadings below. */
+const CHART_READINGS_LIMIT = 1000
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+interface EnergyChartsProps {
+  /** UUID of the Modbus device to chart. */
+  uuid: string
+  /** Friendly name for the chart title. */
+  deviceName: string
+  /** Auto-refresh options forwarded to useReadings. */
+  autoRefresh?: AutoRefreshOptions
+}
+
+// ---------------------------------------------------------------------------
+// Time-range presets
+// ---------------------------------------------------------------------------
+
+interface TimePreset {
+  label: string
+  value: string
+  /** How many milliseconds of history to show. */
+  spanMs: number
+}
+
+const TIME_PRESETS: TimePreset[] = [
+  { label: '1 h', value: '1h', spanMs: 60 * 60 * 1000 },
+  { label: '6 h', value: '6h', spanMs: 6 * 60 * 60 * 1000 },
+  { label: '24 h', value: '24h', spanMs: 24 * 60 * 60 * 1000 },
+]
+
+const DEFAULT_PRESET = '1h'
+
+// ---------------------------------------------------------------------------
+// Metric colour palette — cycles through a fixed set
+// ---------------------------------------------------------------------------
+
+const LINE_COLORS = [
+  '#4c9cdb',
+  '#f59f00',
+  '#51cf66',
+  '#f03e3e',
+  '#cc5de8',
+  '#20c997',
+  '#fd7e14',
+  '#74c0fc',
+]
+
+function lineColor(index: number): string {
+  return LINE_COLORS[index % LINE_COLORS.length]
+}
+
+// ---------------------------------------------------------------------------
+// Helper: format a recorded_at timestamp for the X-axis tick
+// ---------------------------------------------------------------------------
+
+function formatTimeTick(isoString: string): string {
+  return formatLocalTime(isoString)
+}
+
+// ---------------------------------------------------------------------------
+// Helper: safe numeric read from payload — returns null if key absent/non-numeric
+// ---------------------------------------------------------------------------
+
+function safePayloadValue(
+  payload: Record<string, unknown> | null | undefined,
+  key: string,
+): number | null {
+  if (!payload) return null
+  const raw = payload[key]
+  if (raw === null || raw === undefined) return null
+  const n = Number(raw)
+  return Number.isFinite(n) ? n : null
+}
+
+// ---------------------------------------------------------------------------
+// EnergyCharts component
+// ---------------------------------------------------------------------------
+
+export function EnergyCharts({ uuid, deviceName, autoRefresh }: EnergyChartsProps) {
+  const [activePreset, setActivePreset] = useState<string>(DEFAULT_PRESET)
+
+  const selectedPreset = TIME_PRESETS.find((p) => p.value === activePreset) ?? TIME_PRESETS[0]
+
+  // Pass spanMs rather than fixed start/end so that every refetchInterval-triggered
+  // queryFn call computes end=now() and rolls the window forward — new readings
+  // recorded after mount will appear without a manual page refresh.
+  // Switching presets changes spanMs → different queryKey → immediate re-fetch.
+  const readingsQuery = useReadings(
+    uuid,
+    { spanMs: selectedPreset.spanMs, limit: CHART_READINGS_LIMIT },
+    autoRefresh,
+  )
+  const metricsQuery = useMetrics(uuid)
+
+  // -------------------------------------------------------------------------
+  // Derive chart data: [{recorded_at, voltage: 230.2, current: 1.3, ...}, ...]
+  // -------------------------------------------------------------------------
+
+  const metricsData = metricsQuery.data?.metrics
+
+  const chartData = useMemo(() => {
+    const metrics: MetricInfo[] = metricsData ?? []
+    const readings = readingsQuery.data?.items ?? []
+    return readings.map((row) => {
+      const point: Record<string, string | number | null> = {
+        recorded_at: row.recorded_at,
+      }
+      for (const m of metrics) {
+        // Tolerate missing keys — null produces a gap in the line, not a crash.
+        point[m.key] = safePayloadValue(row.payload as Record<string, unknown>, m.key)
+      }
+      return point
+    })
+  }, [readingsQuery.data, metricsData])
+
+  const metrics: MetricInfo[] = metricsQuery.data?.metrics ?? []
+
+  // -------------------------------------------------------------------------
+  // States: loading / error / empty
+  // -------------------------------------------------------------------------
+
+  const isLoading = readingsQuery.isLoading || metricsQuery.isLoading
+  const isError = readingsQuery.isError || metricsQuery.isError
+
+  /**
+   * True when the returned row count equals the limit cap, meaning the window
+   * contains more data than was fetched.  The backend returns the most-recent N
+   * rows in this case, so the chart shows the latest segment — but a hint is
+   * shown so the user knows the full window is not displayed.
+   */
+  const isTruncated =
+    !isLoading &&
+    !isError &&
+    (readingsQuery.data?.items.length ?? 0) >= CHART_READINGS_LIMIT
+
+  return (
+    <Paper withBorder p="md" data-testid={`energy-charts-${uuid}`}>
+      <Stack gap="sm">
+        {/* Header row */}
+        <Group justify="space-between" align="center" wrap="nowrap">
+          <Title order={4} data-testid={`energy-charts-title-${uuid}`}>
+            {deviceName}
+          </Title>
+          <SegmentedControl
+            size="xs"
+            value={activePreset}
+            onChange={setActivePreset}
+            data={TIME_PRESETS.map((p) => ({ value: p.value, label: p.label }))}
+            data-testid={`energy-charts-preset-${uuid}`}
+          />
+        </Group>
+
+        {/* Loading */}
+        {isLoading && (
+          <Group justify="center" py="lg" data-testid={`energy-charts-loading-${uuid}`}>
+            <Loader size="sm" />
+            <Text size="sm" c="dimmed">
+              Loading readings…
+            </Text>
+          </Group>
+        )}
+
+        {/* Error */}
+        {!isLoading && isError && (
+          <Alert color="red" data-testid={`energy-charts-error-${uuid}`}>
+            Failed to load readings or metrics. Please try again.
+          </Alert>
+        )}
+
+        {/* Empty */}
+        {!isLoading && !isError && chartData.length === 0 && (
+          <Text
+            size="sm"
+            c="dimmed"
+            ta="center"
+            py="lg"
+            data-testid={`energy-charts-empty-${uuid}`}
+          >
+            No readings in this time window.
+          </Text>
+        )}
+
+        {/* Truncation notice — shown when window has more data than the fetch limit */}
+        {isTruncated && (
+          <Text
+            size="xs"
+            c="dimmed"
+            ta="right"
+            data-testid={`energy-charts-truncated-${uuid}`}
+          >
+            Showing the most recent {CHART_READINGS_LIMIT} readings; full long-range trend pending downsampling
+          </Text>
+        )}
+
+        {/* Chart */}
+        {!isLoading && !isError && chartData.length > 0 && (
+          <Box data-testid={`energy-charts-chart-${uuid}`}>
+            {/* Render one chart per metric for clarity (avoids mixed Y-axis units) */}
+            {metrics.map((metric, idx) => {
+              // Check if this metric has any non-null data points; skip if all null.
+              const hasData = chartData.some((pt) => pt[metric.key] !== null)
+              if (!hasData) return null
+
+              return (
+                <Box key={metric.key} mb="md">
+                  <Group gap="xs" mb={4}>
+                    <Text size="xs" fw={600} c="dimmed">
+                      {metric.label}
+                    </Text>
+                    {metric.unit && (
+                      <Badge size="xs" variant="outline" color="gray">
+                        {metric.unit}
+                      </Badge>
+                    )}
+                  </Group>
+                  <ResponsiveContainer width="100%" height={160}>
+                    <LineChart
+                      data={chartData}
+                      margin={{ top: 4, right: 8, left: 0, bottom: 0 }}
+                    >
+                      <CartesianGrid strokeDasharray="3 3" opacity={0.4} />
+                      <XAxis
+                        dataKey="recorded_at"
+                        tickFormatter={formatTimeTick}
+                        tick={{ fontSize: 10 }}
+                        minTickGap={40}
+                      />
+                      <YAxis
+                        tick={{ fontSize: 10 }}
+                        width={50}
+                        tickFormatter={(v: number) =>
+                          metric.unit ? `${v} ${metric.unit}` : String(v)
+                        }
+                      />
+                      <RechartsTooltip
+                        formatter={(value) => {
+                          const formatted = formatMetricValue(value, metric)
+                          if (formatted === '—') return ['—', metric.label] as [string, string]
+                          return [
+                            `${formatted}${metric.unit ? ' ' + metric.unit : ''}`,
+                            metric.label,
+                          ] as [string, string]
+                        }}
+                        labelFormatter={(label) => {
+                          return formatLocalDateTime(String(label))
+                        }}
+                      />
+                      <Legend />
+                      <Line
+                        type="monotone"
+                        dataKey={metric.key}
+                        name={metric.label}
+                        stroke={lineColor(idx)}
+                        dot={false}
+                        isAnimationActive={false}
+                        connectNulls={false}
+                      />
+                    </LineChart>
+                  </ResponsiveContainer>
+                </Box>
+              )
+            })}
+          </Box>
+        )}
+      </Stack>
+    </Paper>
+  )
+}
@@ -0,0 +1,446 @@
+/**
+ * Tests for MeterManager component.
+ *
+ * Coverage:
+ * 1. Loading state rendering.
+ * 2. Error state rendering.
+ * 3. Empty state when no meters exist.
+ * 4. Meter timeline list rendering (label, dates, active badge, reason).
+ * 5. "Declare New Meter" button opens form modal.
+ * 6. Declare meter — form submit calls POST /api/energy/meters.
+ * 7. Declare meter — 422 (倒挂) error is displayed.
+ * 8. Edit button opens edit form modal.
+ * 9. Edit meter — saves label/note via PATCH /api/energy/meters/{meter_id}.
+ * 10. Edit meter — retroactive started_at triggers recompute notice.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { renderWithProviders } from '../test-utils'
+import { MeterManager } from './MeterManager'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+const mockPatch = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: (...args: unknown[]) => mockPatch(...args),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const ACTIVE_METER = {
+  id: 1,
+  label: 'Initial 2G meter',
+  commodity: 'electricity',
+  started_at: '2024-01-15T00:00:00Z',
+  ended_at: null,
+  reason: 'initial',
+  note: null,
+  created_at: '2024-01-15T00:00:00Z',
+}
+
+const CLOSED_METER = {
+  id: 2,
+  label: 'Old 4G meter',
+  commodity: 'electricity',
+  started_at: '2023-06-01T00:00:00Z',
+  ended_at: '2024-01-15T00:00:00Z',
+  reason: 'meter_swap',
+  note: 'Replaced by grid company',
+  created_at: '2023-06-01T00:00:00Z',
+}
+
+const METERS_RESPONSE = {
+  items: [CLOSED_METER, ACTIVE_METER],
+  total: 2,
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('MeterManager — loading / error / empty states', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders loading state initially', () => {
+    mockGet.mockImplementation(() => new Promise(() => {}))
+
+    renderWithProviders(<MeterManager />)
+
+    expect(screen.getByTestId('meters-loading')).toBeInTheDocument()
+  })
+
+  it('renders error state when GET fails', async () => {
+    mockGet.mockRejectedValue(new Error('Network error'))
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('meters-load-error')).toBeInTheDocument()
+    })
+  })
+
+  it('renders empty state when no meters exist', async () => {
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('meters-empty')).toBeInTheDocument()
+    })
+  })
+})
+
+describe('MeterManager — meter list', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders meter timeline with label, dates, status badge, reason', async () => {
+    mockGet.mockResolvedValue({ data: METERS_RESPONSE })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('meters-table')).toBeInTheDocument()
+    })
+
+    // Labels
+    expect(screen.getByText('Initial 2G meter')).toBeInTheDocument()
+    expect(screen.getByText('Old 4G meter')).toBeInTheDocument()
+
+    // Status badges
+    expect(screen.getByTestId(`meter-status-${ACTIVE_METER.id}`)).toHaveTextContent('active')
+    expect(screen.getByTestId(`meter-status-${CLOSED_METER.id}`)).toHaveTextContent('closed')
+
+    // Reason badges
+    expect(screen.getByText('initial')).toBeInTheDocument()
+    expect(screen.getByText('meter_swap')).toBeInTheDocument()
+  })
+
+  it('renders "Declare New Meter" button', async () => {
+    mockGet.mockResolvedValue({ data: METERS_RESPONSE })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument()
+    })
+  })
+})
+
+describe('MeterManager — declare new meter', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('opens declare modal when "Declare New Meter" is clicked', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
+
+    await user.click(screen.getByTestId('meter-declare-button'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('declare-meter-modal')).toBeInTheDocument()
+    })
+    expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument()
+  })
+
+  it('calls POST /api/energy/meters with correct payload including local-midnight naive datetime', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+    mockPost.mockResolvedValue({ data: ACTIVE_METER })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
+    await user.click(screen.getByTestId('meter-declare-button'))
+
+    await waitFor(() => expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument())
+
+    // Fill form
+    await user.type(screen.getByTestId('meter-label'), 'New meter label')
+    await user.type(screen.getByTestId('meter-started-at'), '2026-01-01')
+
+    // Select reason via the combobox (Mantine Select renders a combobox)
+    await user.click(screen.getByTestId('meter-reason'))
+    await waitFor(() => screen.getByText('Initial installation'))
+    await user.click(screen.getByText('Initial installation'))
+
+    await user.click(screen.getByTestId('declare-meter-submit'))
+
+    await waitFor(() => {
+      expect(mockPost).toHaveBeenCalledWith(
+        '/api/energy/meters',
+        expect.objectContaining({
+          body: expect.objectContaining({
+            label: 'New meter label',
+            // FU10 local-midnight naive convention: no Z suffix
+            started_at: '2026-01-01T00:00:00',
+            reason: 'initial',
+            commodity: 'electricity',
+          }),
+        }),
+      )
+    })
+  })
+
+  it('displays error when POST fails with 422 (倒挂 / validation error)', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+
+    const { ApiError } = await import('../api/client')
+    mockPost.mockRejectedValue(
+      new ApiError(422, { detail: 'started_at must be ≥ current active meter started_at' }),
+    )
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
+    await user.click(screen.getByTestId('meter-declare-button'))
+    await waitFor(() => expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument())
+
+    await user.type(screen.getByTestId('meter-label'), 'Bad meter')
+    await user.type(screen.getByTestId('meter-started-at'), '2020-01-01')
+    await user.click(screen.getByTestId('meter-reason'))
+    await waitFor(() => screen.getByText('Meter swap (same address)'))
+    await user.click(screen.getByText('Meter swap (same address)'))
+
+    await user.click(screen.getByTestId('declare-meter-submit'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('declare-meter-error')).toBeInTheDocument()
+    })
+    expect(screen.getByTestId('declare-meter-error').textContent).toContain(
+      'started_at must be ≥',
+    )
+  })
+
+  it('cancel button closes the declare modal', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
+    await user.click(screen.getByTestId('meter-declare-button'))
+    await waitFor(() => expect(screen.getByTestId('declare-meter-modal')).toBeInTheDocument())
+
+    await user.click(screen.getByTestId('declare-meter-cancel'))
+
+    await waitFor(() => {
+      expect(screen.queryByTestId('declare-meter-modal')).not.toBeInTheDocument()
+    })
+  })
+})
+
+describe('MeterManager — edit meter date initialisation', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('initialises date input from started_at (Z-suffix, UTC midnight → local date)', async () => {
+    // ACTIVE_METER.started_at = '2024-01-15T00:00:00Z' (UTC midnight).
+    // The test suite is pinned to TZ=UTC (via vite.config.ts test.env), so
+    // the local date is deterministically '2024-01-15' on any CI runner.
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
+    expect(dateInput.value).toBe('2024-01-15')
+  })
+
+  it('initialises date input from started_at (naive, no tz marker)', async () => {
+    // A naive timestamp without timezone marker — parseBackendTimestamp appends 'Z'
+    // so it is treated as UTC. With TZ=UTC (pinned in vite.config.ts), the local date
+    // equals the UTC date exactly.
+    const naiveMeter = { ...ACTIVE_METER, started_at: '2024-03-20T00:00:00' }
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [naiveMeter], total: 1 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${naiveMeter.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${naiveMeter.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
+    expect(dateInput.value).toBe('2024-03-20')
+  })
+
+  it('initialises date input from started_at with explicit UTC offset (+02:00) — regression for old buggy regex', async () => {
+    // The old hand-written regex /[zZ+-]\d*$/ would fail to match '+02:00' (the ':00'
+    // suffix broke the pattern) and would incorrectly append 'Z', producing an Invalid Date.
+    // The new code uses parseBackendTimestamp which uses the correct TZ_MARKER_RE regex
+    // and handles explicit offsets properly.
+    const offsetMeter = { ...ACTIVE_METER, started_at: '2024-01-15T02:00:00+02:00' }
+    // UTC equivalent: 2024-01-15T00:00:00Z → with TZ=UTC (pinned) local date = '2024-01-15'
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [offsetMeter], total: 1 } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${offsetMeter.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${offsetMeter.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
+    // Must not be empty (which would indicate Invalid Date from the old buggy path)
+    expect(dateInput.value).not.toBe('')
+    expect(dateInput.value).toBe('2024-01-15')
+  })
+
+  it('does not include started_at in PATCH body when date is unchanged (round-trip idempotence)', async () => {
+    // Open the edit form and immediately submit without changing any fields except label.
+    // The date should be considered unchanged → no started_at in the PATCH body.
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, label: 'New label' } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    // Change only label; leave date untouched
+    const labelInput = screen.getByTestId('edit-meter-label')
+    await user.clear(labelInput)
+    await user.type(labelInput, 'New label')
+
+    await user.click(screen.getByTestId('edit-meter-submit'))
+
+    await waitFor(() => {
+      expect(mockPatch).toHaveBeenCalled()
+    })
+
+    const patchBody = mockPatch.mock.calls[0][1].body
+    expect(patchBody).not.toHaveProperty('started_at')
+  })
+})
+
+describe('MeterManager — edit meter', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('opens edit modal when Edit button is clicked', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: METERS_RESPONSE })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('edit-meter-modal')).toBeInTheDocument()
+    })
+    expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument()
+  })
+
+  it('calls PATCH /api/energy/meters/{meter_id} when label is changed', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, label: 'Renamed meter' } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    // Clear label and type new one
+    const labelInput = screen.getByTestId('edit-meter-label')
+    await user.clear(labelInput)
+    await user.type(labelInput, 'Renamed meter')
+
+    await user.click(screen.getByTestId('edit-meter-submit'))
+
+    await waitFor(() => {
+      expect(mockPatch).toHaveBeenCalledWith(
+        '/api/energy/meters/{meter_id}',
+        expect.objectContaining({
+          params: { path: { meter_id: ACTIVE_METER.id } },
+          body: expect.objectContaining({ label: 'Renamed meter' }),
+        }),
+      )
+    })
+  })
+
+  it('shows recompute notice when started_at is changed (retroactive correction)', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, started_at: '2024-02-01T00:00:00' } })
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    // Change the date field
+    const dateInput = screen.getByTestId('edit-meter-started-at')
+    await user.clear(dateInput)
+    await user.type(dateInput, '2024-02-01')
+
+    await user.click(screen.getByTestId('edit-meter-submit'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('meter-recompute-notice')).toBeInTheDocument()
+    })
+  })
+
+  it('displays error when PATCH fails', async () => {
+    const user = userEvent.setup()
+    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
+
+    const { ApiError } = await import('../api/client')
+    mockPatch.mockRejectedValue(new ApiError(422, { detail: 'started_at conflict' }))
+
+    renderWithProviders(<MeterManager />)
+
+    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
+    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
+    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())
+
+    // Change label so there's something to patch
+    const labelInput = screen.getByTestId('edit-meter-label')
+    await user.clear(labelInput)
+    await user.type(labelInput, 'Different label')
+
+    await user.click(screen.getByTestId('edit-meter-submit'))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('edit-meter-error')).toBeInTheDocument()
+    })
+    expect(screen.getByTestId('edit-meter-error').textContent).toContain('started_at conflict')
+  })
+})
@@ -0,0 +1,503 @@
+/**
+ * MeterManager — electricity meter timeline UI.
+ *
+ * Features:
+ * - Table of meter epochs: label / interval (started_at → ended_at or "active") /
+ *   active badge / reason.
+ * - "Declare New Meter" button: form with label + date (started_at) + reason +
+ *   optional note.  Sends local-midnight naive datetime per FU10 convention.
+ * - Edit modal: update label, note, or correct started_at (retroactive).
+ * - Retroactive feedback: if started_at is changed, a success notice mentions
+ *   that affected billing periods have been recomputed.
+ * - Loading / error / empty states.
+ */
+
+import { useState } from 'react'
+import {
+  Table,
+  Button,
+  Group,
+  Text,
+  Loader,
+  Center,
+  Alert,
+  Stack,
+  Badge,
+  ScrollArea,
+  Modal,
+  TextInput,
+  Textarea,
+  Select,
+  Notification,
+} from '@mantine/core'
+import {
+  useMeters,
+  useDeclareMeter,
+  useUpdateMeter,
+  type MeterResponse,
+  type MeterReason,
+} from './hooks'
+import { ApiError } from '../api/client'
+import { formatLocalDate, parseBackendTimestamp } from '../utils/datetime'
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+const REASON_OPTIONS: { value: MeterReason; label: string }[] = [
+  { value: 'initial', label: 'Initial installation' },
+  { value: 'meter_swap', label: 'Meter swap (same address)' },
+  { value: 'home_move', label: 'Home / address move' },
+  { value: 'other', label: 'Other' },
+]
+
+/**
+ * Convert a local date string "YYYY-MM-DD" to a naive local-midnight datetime
+ * string (no Z suffix) following the FU10 / ContractForm convention.
+ * The backend interprets naive datetimes as server local wall-clock time.
+ */
+function toLocalMidnightNaive(dateStr: string): string {
+  return `${dateStr}T00:00:00`
+}
+
+/**
+ * Format a Date object as a "YYYY-MM-DD" string using the browser's local timezone.
+ * Used to populate <input type="date"> fields.
+ * Returns '' if the Date is invalid.
+ */
+function toLocalDateInputString(d: Date): string {
+  if (isNaN(d.getTime())) return ''
+  const y = d.getFullYear()
+  const m = String(d.getMonth() + 1).padStart(2, '0')
+  const day = String(d.getDate()).padStart(2, '0')
+  return `${y}-${m}-${day}`
+}
+
+// ---------------------------------------------------------------------------
+// Declare meter form (modal)
+// ---------------------------------------------------------------------------
+
+interface DeclareMeterFormProps {
+  onClose: () => void
+  onSaved: () => void
+}
+
+function DeclareMeterForm({ onClose, onSaved }: DeclareMeterFormProps) {
+  const [label, setLabel] = useState('')
+  const [dateStr, setDateStr] = useState('')
+  const [reason, setReason] = useState<string | null>(null)
+  const [note, setNote] = useState('')
+  const [error, setError] = useState<string | null>(null)
+
+  const declareMutation = useDeclareMeter()
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setError(null)
+
+    if (!label.trim()) {
+      setError('Label is required.')
+      return
+    }
+    if (!dateStr) {
+      setError('Start date is required.')
+      return
+    }
+    if (!reason) {
+      setError('Reason is required.')
+      return
+    }
+
+    try {
+      await declareMutation.mutateAsync({
+        label: label.trim(),
+        started_at: toLocalMidnightNaive(dateStr),
+        reason: reason as MeterReason,
+        note: note.trim() || undefined,
+        commodity: 'electricity',
+      })
+      onSaved()
+      onClose()
+    } catch (err) {
+      if (err instanceof ApiError) {
+        const detail = (err.body as { detail?: string } | null)?.detail
+        setError(detail ?? `Error ${err.status}: failed to declare meter.`)
+      } else {
+        setError('Failed to declare meter. Please try again.')
+      }
+    }
+  }
+
+  return (
+    <Modal
+      opened
+      onClose={onClose}
+      title="Declare New Meter"
+      size="md"
+      data-testid="declare-meter-modal"
+    >
+      <form onSubmit={handleSubmit} data-testid="declare-meter-form">
+        <Stack gap="sm">
+          <TextInput
+            label="Label"
+            description={'Human-readable identifier, e.g. "2G meter @ Dorpsstraat 1"'}
+            required
+            value={label}
+            onChange={(e) => setLabel(e.currentTarget.value)}
+            data-testid="meter-label"
+          />
+
+          <TextInput
+            label="Start date"
+            description="Date in YYYY-MM-DD format (interpreted as local midnight)"
+            type="date"
+            required
+            value={dateStr}
+            onChange={(e) => setDateStr(e.currentTarget.value)}
+            data-testid="meter-started-at"
+          />
+
+          <Select
+            label="Reason"
+            required
+            data={REASON_OPTIONS}
+            value={reason}
+            onChange={setReason}
+            data-testid="meter-reason"
+          />
+
+          <Textarea
+            label="Note (optional)"
+            value={note}
+            onChange={(e) => setNote(e.currentTarget.value)}
+            autosize
+            minRows={2}
+            data-testid="meter-note"
+          />
+
+          {error && (
+            <Alert color="red" data-testid="declare-meter-error">
+              {error}
+            </Alert>
+          )}
+
+          <Group justify="flex-end" gap="sm">
+            <Button
+              type="button"
+              variant="default"
+              onClick={onClose}
+              data-testid="declare-meter-cancel"
+            >
+              Cancel
+            </Button>
+            <Button
+              type="submit"
+              loading={declareMutation.isPending}
+              data-testid="declare-meter-submit"
+            >
+              Declare Meter
+            </Button>
+          </Group>
+        </Stack>
+      </form>
+    </Modal>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Edit meter form (modal)
+// ---------------------------------------------------------------------------
+
+interface EditMeterFormProps {
+  meter: MeterResponse
+  onClose: () => void
+  onSaved: (retroactive: boolean) => void
+}
+
+function EditMeterForm({ meter, onClose, onSaved }: EditMeterFormProps) {
+  const [label, setLabel] = useState(meter.label)
+  const [note, setNote] = useState(meter.note ?? '')
+  // Convert started_at to a local date string for the <input type="date">.
+  // parseBackendTimestamp correctly handles naive strings (no tz marker → treated as UTC,
+  // matching the backend's storage convention), Z-suffixed strings, and strings with
+  // explicit offsets like +02:00.  We then extract the local-timezone date components
+  // so the displayed date matches the local wall-clock date of the meter start.
+  const initialDateStr = toLocalDateInputString(parseBackendTimestamp(meter.started_at))
+  const [dateStr, setDateStr] = useState(initialDateStr)
+  const [error, setError] = useState<string | null>(null)
+
+  const updateMutation = useUpdateMeter()
+
+  // Detect if the user changed started_at (retroactive correction).
+  const startedAtChanged = dateStr !== initialDateStr
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setError(null)
+
+    const patchBody: { label?: string | null; note?: string | null; started_at?: string | null } = {}
+    if (label.trim() !== meter.label) patchBody.label = label.trim()
+    const noteVal = note.trim() || null
+    if (noteVal !== meter.note) patchBody.note = noteVal
+    if (startedAtChanged && dateStr) {
+      patchBody.started_at = toLocalMidnightNaive(dateStr)
+    }
+
+    if (Object.keys(patchBody).length === 0) {
+      onClose()
+      return
+    }
+
+    try {
+      await updateMutation.mutateAsync({ id: meter.id, body: patchBody })
+      onSaved(startedAtChanged)
+      onClose()
+    } catch (err) {
+      if (err instanceof ApiError) {
+        const detail = (err.body as { detail?: string } | null)?.detail
+        setError(detail ?? `Error ${err.status}: failed to update meter.`)
+      } else {
+        setError('Failed to update meter. Please try again.')
+      }
+    }
+  }
+
+  return (
+    <Modal
+      opened
+      onClose={onClose}
+      title={`Edit Meter — ${meter.label}`}
+      size="md"
+      data-testid="edit-meter-modal"
+    >
+      <form onSubmit={handleSubmit} data-testid="edit-meter-form">
+        <Stack gap="sm">
+          <TextInput
+            label="Label"
+            required
+            value={label}
+            onChange={(e) => setLabel(e.currentTarget.value)}
+            data-testid="edit-meter-label"
+          />
+
+          <TextInput
+            label="Start date"
+            description="Retroactive correction: shifts the epoch boundary and re-judges billing periods"
+            type="date"
+            value={dateStr}
+            onChange={(e) => setDateStr(e.currentTarget.value)}
+            data-testid="edit-meter-started-at"
+          />
+
+          <Textarea
+            label="Note (optional)"
+            value={note}
+            onChange={(e) => setNote(e.currentTarget.value)}
+            autosize
+            minRows={2}
+            data-testid="edit-meter-note"
+          />
+
+          {error && (
+            <Alert color="red" data-testid="edit-meter-error">
+              {error}
+            </Alert>
+          )}
+
+          <Group justify="flex-end" gap="sm">
+            <Button
+              type="button"
+              variant="default"
+              onClick={onClose}
+              data-testid="edit-meter-cancel"
+            >
+              Cancel
+            </Button>
+            <Button
+              type="submit"
+              loading={updateMutation.isPending}
+              data-testid="edit-meter-submit"
+            >
+              Save
+            </Button>
+          </Group>
+        </Stack>
+      </form>
+    </Modal>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Meter timeline table
+// ---------------------------------------------------------------------------
+
+interface MeterTableProps {
+  meters: MeterResponse[]
+  onEdit: (meter: MeterResponse) => void
+}
+
+function MeterTable({ meters, onEdit }: MeterTableProps) {
+  if (meters.length === 0) {
+    return (
+      <Text c="dimmed" ta="center" size="sm" data-testid="meters-empty">
+        No meters declared yet. Click "Declare New Meter" to add one.
+      </Text>
+    )
+  }
+
+  return (
+    <ScrollArea>
+      <Table striped highlightOnHover withTableBorder data-testid="meters-table">
+        <Table.Thead>
+          <Table.Tr>
+            <Table.Th>Label</Table.Th>
+            <Table.Th>Commodity</Table.Th>
+            <Table.Th>From</Table.Th>
+            <Table.Th>To</Table.Th>
+            <Table.Th>Status</Table.Th>
+            <Table.Th>Reason</Table.Th>
+            <Table.Th style={{ textAlign: 'right' }}>Actions</Table.Th>
+          </Table.Tr>
+        </Table.Thead>
+        <Table.Tbody>
+          {meters.map((meter) => {
+            const isActive = meter.ended_at === null
+            return (
+              <Table.Tr key={meter.id} data-testid={`meter-row-${meter.id}`}>
+                <Table.Td>
+                  <Text fw={500} size="sm">
+                    {meter.label}
+                  </Text>
+                </Table.Td>
+                <Table.Td>
+                  <Badge variant="outline" size="sm">
+                    {meter.commodity}
+                  </Badge>
+                </Table.Td>
+                <Table.Td>
+                  <Text size="xs" c="dimmed">
+                    {formatLocalDate(meter.started_at)}
+                  </Text>
+                </Table.Td>
+                <Table.Td>
+                  <Text size="xs" c="dimmed">
+                    {meter.ended_at ? formatLocalDate(meter.ended_at) : '—'}
+                  </Text>
+                </Table.Td>
+                <Table.Td>
+                  <Badge
+                    color={isActive ? 'green' : 'gray'}
+                    variant="light"
+                    size="sm"
+                    data-testid={`meter-status-${meter.id}`}
+                  >
+                    {isActive ? 'active' : 'closed'}
+                  </Badge>
+                </Table.Td>
+                <Table.Td>
+                  <Badge variant="outline" size="sm" color="blue">
+                    {meter.reason}
+                  </Badge>
+                </Table.Td>
+                <Table.Td>
+                  <Group justify="flex-end" gap="xs">
+                    <Button
+                      size="xs"
+                      variant="outline"
+                      onClick={() => onEdit(meter)}
+                      data-testid={`meter-edit-${meter.id}`}
+                    >
+                      Edit
+                    </Button>
+                  </Group>
+                </Table.Td>
+              </Table.Tr>
+            )
+          })}
+        </Table.Tbody>
+      </Table>
+    </ScrollArea>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// MeterManager — top-level
+// ---------------------------------------------------------------------------
+
+export function MeterManager() {
+  const metersQuery = useMeters()
+
+  const [showDeclareForm, setShowDeclareForm] = useState(false)
+  const [editMeter, setEditMeter] = useState<MeterResponse | null>(null)
+  const [recomputeNotice, setRecomputeNotice] = useState(false)
+
+  // ---------------------------------------------------------------------------
+  // Render states
+  // ---------------------------------------------------------------------------
+
+  if (metersQuery.isLoading) {
+    return (
+      <Center py="xl" data-testid="meters-loading">
+        <Loader />
+      </Center>
+    )
+  }
+
+  if (metersQuery.isError || !metersQuery.data) {
+    return (
+      <Alert color="red" data-testid="meters-load-error">
+        Failed to load meters. Please refresh.
+      </Alert>
+    )
+  }
+
+  const meters = metersQuery.data.items
+
+  return (
+    <Stack gap="lg" data-testid="meter-manager">
+      <Group justify="space-between" align="center">
+        <Text fw={500}>Electricity Meters</Text>
+        <Button
+          onClick={() => setShowDeclareForm(true)}
+          data-testid="meter-declare-button"
+        >
+          Declare New Meter
+        </Button>
+      </Group>
+
+      {recomputeNotice && (
+        <Notification
+          color="teal"
+          title="Billing periods recomputed"
+          onClose={() => setRecomputeNotice(false)}
+          data-testid="meter-recompute-notice"
+        >
+          The start date was corrected. Affected billing periods have been
+          re-judged and cost attributions updated.
+        </Notification>
+      )}
+
+      <MeterTable meters={meters} onEdit={(m) => setEditMeter(m)} />
+
+      {/* Declare new meter */}
+      {showDeclareForm && (
+        <DeclareMeterForm
+          onClose={() => setShowDeclareForm(false)}
+          onSaved={() => setShowDeclareForm(false)}
+        />
+      )}
+
+      {/* Edit existing meter */}
+      {editMeter && (
+        <EditMeterForm
+          meter={editMeter}
+          onClose={() => setEditMeter(null)}
+          onSaved={(retroactive) => {
+            setEditMeter(null)
+            if (retroactive) setRecomputeNotice(true)
+          }}
+        />
+      )}
+    </Stack>
+  )
+}
@@ -0,0 +1,138 @@
+/**
+ * Tests for TibberPrices component.
+ *
+ * Coverage:
+ * 1. Loading state.
+ * 2. Empty state (no active contract / no kind).
+ * 3. Renders tibber chart when tibber kind data is available.
+ * 4. Shows tariff table for manual kind.
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, waitFor } from '@testing-library/react'
+import { renderWithProviders } from '../test-utils'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: vi.fn(),
+    PATCH: vi.fn(),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Import component
+// ---------------------------------------------------------------------------
+
+import { TibberPrices } from './TibberPrices'
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('TibberPrices', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('renders loading state initially', () => {
+    mockGet.mockImplementation(() => new Promise(() => {}))
+
+    renderWithProviders(<TibberPrices />)
+
+    expect(screen.getByTestId('prices-loading')).toBeInTheDocument()
+  })
+
+  it('renders "no active contract" when kind is missing/null', async () => {
+    mockGet.mockResolvedValue({
+      data: {
+        kind: null,
+        currency: 'EUR',
+        points: [],
+        tariff: null,
+      },
+    })
+
+    renderWithProviders(<TibberPrices />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('prices-no-contract')).toBeInTheDocument()
+    })
+  })
+
+  it('renders error state when fetch fails', async () => {
+    mockGet.mockRejectedValue(new Error('Network error'))
+
+    renderWithProviders(<TibberPrices />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('prices-error')).toBeInTheDocument()
+    })
+  })
+
+  it('renders tibber chart when tibber data is available', async () => {
+    mockGet.mockResolvedValue({
+      data: {
+        kind: 'tibber',
+        currency: 'EUR',
+        points: [
+          { starts_at: '2026-06-22T10:00:00Z', buy: 0.133, sell: 0.09, level: 'NORMAL' },
+          { starts_at: '2026-06-22T10:15:00Z', buy: 0.140, sell: 0.092, level: 'NORMAL' },
+        ],
+        tariff: null,
+      },
+    })
+
+    renderWithProviders(<TibberPrices />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('tibber-chart')).toBeInTheDocument()
+    })
+
+    // Check badge shows kind
+    expect(screen.getByText('tibber')).toBeInTheDocument()
+  })
+
+  it('shows tariff table for manual kind', async () => {
+    mockGet.mockResolvedValue({
+      data: {
+        kind: 'manual',
+        currency: 'EUR',
+        points: [],
+        tariff: {
+          buy_dal: 0.127,
+          buy_normal: 0.133,
+          sell_dal: 0.09,
+          sell_normal: 0.09,
+        },
+      },
+    })
+
+    renderWithProviders(<TibberPrices />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('manual-tariff-table')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('tariff-buy-normal')).toHaveTextContent('0.1330')
+    expect(screen.getByTestId('tariff-buy-dal')).toHaveTextContent('0.1270')
+    expect(screen.getByTestId('tariff-sell-normal')).toHaveTextContent('0.0900')
+    expect(screen.getByTestId('tariff-sell-dal')).toHaveTextContent('0.0900')
+  })
+})
@@ -0,0 +1,244 @@
+/**
+ * TibberPrices — price curve visualization.
+ *
+ * - Fetches today + tomorrow price range using useEnergyPrices.
+ * - For tibber kind: Recharts LineChart showing buy/sell prices over time.
+ * - For manual kind: shows tariff table (buy_dal, buy_normal, sell_dal, sell_normal).
+ * - Handles: no active contract, empty data, loading, error.
+ *
+ * Recharts imports are isolated to this file only.
+ */
+
+import {
+  Stack,
+  Text,
+  Loader,
+  Center,
+  Alert,
+  Table,
+  Title,
+  Badge,
+  Group,
+  Paper,
+} from '@mantine/core'
+import {
+  LineChart,
+  Line,
+  XAxis,
+  YAxis,
+  CartesianGrid,
+  Tooltip,
+  Legend,
+  ResponsiveContainer,
+} from 'recharts'
+import { useEnergyPrices } from './hooks'
+import { formatLocalTime } from '../utils/datetime'
+
+// ---------------------------------------------------------------------------
+// Time range helpers
+// ---------------------------------------------------------------------------
+
+function getTodayStart(): string {
+  const d = new Date()
+  d.setUTCHours(0, 0, 0, 0)
+  return d.toISOString()
+}
+
+function getTomorrowEnd(): string {
+  const d = new Date()
+  d.setUTCHours(0, 0, 0, 0)
+  d.setUTCDate(d.getUTCDate() + 2)
+  return d.toISOString()
+}
+
+// ---------------------------------------------------------------------------
+// Tibber chart
+// ---------------------------------------------------------------------------
+
+interface TibberChartProps {
+  points: Array<{ starts_at: string; buy: number; sell: number; level?: string | null }>
+  currency: string
+}
+
+function TibberChart({ points, currency }: TibberChartProps) {
+  const data = points.map((p) => ({
+    time: formatLocalTime(p.starts_at),
+    buy: p.buy,
+    sell: p.sell,
+  }))
+
+  return (
+    <Stack gap="xs" data-testid="tibber-chart">
+      <Title order={6} c="dimmed">
+        Price curve ({currency})
+      </Title>
+      <ResponsiveContainer width="100%" height={260}>
+        <LineChart data={data} margin={{ top: 4, right: 16, left: 0, bottom: 4 }}>
+          <CartesianGrid strokeDasharray="3 3" />
+          <XAxis
+            dataKey="time"
+            tick={{ fontSize: 10 }}
+            interval="preserveStartEnd"
+          />
+          <YAxis
+            tick={{ fontSize: 10 }}
+            tickFormatter={(v: number) => v.toFixed(3)}
+          />
+          <Tooltip
+            // eslint-disable-next-line @typescript-eslint/no-explicit-any
+            formatter={(val: any) =>
+              [`${typeof val === 'number' ? val.toFixed(4) : String(val)} ${currency}`, undefined]
+            }
+          />
+          <Legend />
+          <Line
+            type="monotone"
+            dataKey="buy"
+            stroke="#2196f3"
+            dot={false}
+            strokeWidth={2}
+            name="Buy"
+          />
+          <Line
+            type="monotone"
+            dataKey="sell"
+            stroke="#4caf50"
+            dot={false}
+            strokeWidth={2}
+            name="Sell"
+          />
+        </LineChart>
+      </ResponsiveContainer>
+    </Stack>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// Manual tariff table
+// ---------------------------------------------------------------------------
+
+interface ManualTariffTableProps {
+  tariff: {
+    buy_dal: number
+    buy_normal: number
+    sell_dal: number
+    sell_normal: number
+  }
+  currency: string
+}
+
+function ManualTariffTable({ tariff, currency }: ManualTariffTableProps) {
+  return (
+    <Stack gap="xs" data-testid="manual-tariff-table">
+      <Title order={6} c="dimmed">
+        Fixed tariff ({currency}/kWh)
+      </Title>
+      <Table withTableBorder withColumnBorders>
+        <Table.Thead>
+          <Table.Tr>
+            <Table.Th>Tariff</Table.Th>
+            <Table.Th>Buy</Table.Th>
+            <Table.Th>Sell</Table.Th>
+          </Table.Tr>
+        </Table.Thead>
+        <Table.Tbody>
+          <Table.Tr>
+            <Table.Td>Normal (peak)</Table.Td>
+            <Table.Td data-testid="tariff-buy-normal">{tariff.buy_normal.toFixed(4)}</Table.Td>
+            <Table.Td data-testid="tariff-sell-normal">{tariff.sell_normal.toFixed(4)}</Table.Td>
+          </Table.Tr>
+          <Table.Tr>
+            <Table.Td>Dal (off-peak)</Table.Td>
+            <Table.Td data-testid="tariff-buy-dal">{tariff.buy_dal.toFixed(4)}</Table.Td>
+            <Table.Td data-testid="tariff-sell-dal">{tariff.sell_dal.toFixed(4)}</Table.Td>
+          </Table.Tr>
+        </Table.Tbody>
+      </Table>
+    </Stack>
+  )
+}
+
+// ---------------------------------------------------------------------------
+// TibberPrices — main component
+// ---------------------------------------------------------------------------
+
+export function TibberPrices() {
+  const start = getTodayStart()
+  const end = getTomorrowEnd()
+
+  const { data, isLoading, isError } = useEnergyPrices(start, end)
+
+  if (isLoading) {
+    return (
+      <Center py="xl" data-testid="prices-loading">
+        <Loader />
+      </Center>
+    )
+  }
+
+  if (isError) {
+    return (
+      <Alert color="red" data-testid="prices-error">
+        Failed to load energy prices. Please refresh.
+      </Alert>
+    )
+  }
+
+  if (!data) {
+    return (
+      <Alert color="gray" data-testid="prices-no-data">
+        No pricing data available.
+      </Alert>
+    )
+  }
+
+  // No active contract
+  if (!data.kind) {
+    return (
+      <Paper withBorder p="md" data-testid="prices-no-contract">
+        <Stack gap="xs">
+          <Text fw={500}>No active contract</Text>
+          <Text size="sm" c="dimmed">
+            Activate an energy contract on the Contracts tab to see pricing data.
+          </Text>
+        </Stack>
+      </Paper>
+    )
+  }
+
+  const currency = data.currency
+
+  return (
+    <Stack gap="lg" data-testid="tibber-prices">
+      <Group gap="sm" align="center">
+        <Text fw={500}>Energy Prices</Text>
+        <Badge variant="outline" size="sm">
+          {data.kind}
+        </Badge>
+        <Text size="xs" c="dimmed">
+          {currency}
+        </Text>
+      </Group>
+
+      {data.kind === 'tibber' && data.points && data.points.length > 0 && (
+        <TibberChart points={data.points} currency={currency} />
+      )}
+
+      {data.kind === 'tibber' && (!data.points || data.points.length === 0) && (
+        <Alert color="yellow" data-testid="tibber-no-prices">
+          No Tibber price points available for the selected time range. Check Tibber configuration.
+        </Alert>
+      )}
+
+      {data.kind === 'manual' && data.tariff && (
+        <ManualTariffTable tariff={data.tariff} currency={currency} />
+      )}
+
+      {data.kind === 'manual' && !data.tariff && (
+        <Alert color="yellow" data-testid="manual-no-tariff">
+          Manual tariff data not available.
+        </Alert>
+      )}
+    </Stack>
+  )
+}
@@ -0,0 +1,293 @@
+/**
+ * Tests for energy hooks in hooks.ts — energy pricing API wrappers.
+ *
+ * Coverage:
+ * 1. useContracts — GET /api/energy/contracts
+ * 2. useCreateContract — POST /api/energy/contracts
+ * 3. useEnergyPrices — GET /api/energy/prices
+ * 4. useEnergyCosts — GET /api/energy/costs
+ * 5. useEnergyCostSummary — GET /api/energy/costs/summary
+ * 6. useRecomputeCosts — POST /api/energy/costs/recompute
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { renderHook, waitFor, act } from '@testing-library/react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import type { ReactNode } from 'react'
+
+// ---------------------------------------------------------------------------
+// Mock apiClient
+// ---------------------------------------------------------------------------
+
+const mockGet = vi.fn()
+const mockPost = vi.fn()
+const mockPatch = vi.fn()
+
+vi.mock('../api/client', () => ({
+  default: {
+    GET: (...args: unknown[]) => mockGet(...args),
+    POST: (...args: unknown[]) => mockPost(...args),
+    PATCH: (...args: unknown[]) => mockPatch(...args),
+    DELETE: vi.fn(),
+  },
+  ApiError: class ApiError extends Error {
+    status: number
+    body: unknown
+    constructor(status: number, body: unknown) {
+      super(`API error ${status}`)
+      this.name = 'ApiError'
+      this.status = status
+      this.body = body
+    }
+  },
+  registerLoginRedirect: vi.fn(),
+}))
+
+// ---------------------------------------------------------------------------
+// Fixtures
+// ---------------------------------------------------------------------------
+
+const CONTRACT = {
+  id: 1,
+  name: 'Test Contract',
+  kind: 'manual',
+  active: true,
+  currency: 'EUR',
+  created_at: '2026-06-01T00:00:00Z',
+  updated_at: '2026-06-01T00:00:00Z',
+}
+
+const PRICE_POINT = {
+  starts_at: '2026-06-22T10:00:00Z',
+  buy: 0.133,
+  sell: 0.09,
+  level: 'NORMAL',
+}
+
+const COST_PERIOD = {
+  period_start: '2026-06-22T10:00:00Z',
+  d1_kwh: 0.1,
+  d2_kwh: 0.2,
+  r1_kwh: 0.0,
+  r2_kwh: 0.05,
+  import_cost: 0.044,
+  export_revenue: 0.005,
+  net_cost: 0.039,
+  currency: 'EUR',
+  degraded: false,
+  contract_version_id: 1,
+}
+
+const SUMMARY = {
+  currency: 'EUR',
+  metered_import: 10.5,
+  metered_export: 2.3,
+  metered_net: 8.2,
+  fixed_costs: 5.0,
+  credits: 50.0,
+  total_payable: 12.5,
+}
+
+// ---------------------------------------------------------------------------
+// Wrapper
+// ---------------------------------------------------------------------------
+
+function makeWrapper() {
+  const qc = new QueryClient({
+    defaultOptions: { queries: { retry: false }, mutations: { retry: false } },
+  })
+  function Wrapper({ children }: { children: ReactNode }) {
+    return <QueryClientProvider client={qc}>{children}</QueryClientProvider>
+  }
+  return { qc, Wrapper }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe('useContracts', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls GET /api/energy/contracts and returns contract list', async () => {
+    mockGet.mockResolvedValue({ data: { items: [CONTRACT], total: 1 } })
+
+    const { Wrapper } = makeWrapper()
+    const { useContracts } = await import('./hooks')
+    const { result } = renderHook(() => useContracts(), { wrapper: Wrapper })
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+    expect(mockGet).toHaveBeenCalledWith('/api/energy/contracts')
+    expect(result.current.data?.items).toHaveLength(1)
+    expect(result.current.data?.items[0].id).toBe(1)
+  })
+})
+
+describe('useCreateContract', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls POST /api/energy/contracts with the provided body', async () => {
+    mockPost.mockResolvedValue({ data: { ...CONTRACT, versions: [] } })
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    const { Wrapper } = makeWrapper()
+    const { useCreateContract } = await import('./hooks')
+    const { result } = renderHook(() => useCreateContract(), { wrapper: Wrapper })
+
+    const body = {
+      name: 'New Contract',
+      kind: 'manual',
+      currency: 'EUR',
+      values: { energy: { buy: { normal: 0.133 } } },
+    }
+
+    await act(async () => {
+      await result.current.mutateAsync(body)
+    })
+
+    expect(mockPost).toHaveBeenCalledWith('/api/energy/contracts', { body })
+  })
+})
+
+describe('useEnergyPrices', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls GET /api/energy/prices with start and end params', async () => {
+    mockGet.mockResolvedValue({
+      data: {
+        kind: 'tibber',
+        currency: 'EUR',
+        points: [PRICE_POINT],
+        tariff: null,
+      },
+    })
+
+    const { Wrapper } = makeWrapper()
+    const { useEnergyPrices } = await import('./hooks')
+    const start = '2026-06-22T00:00:00Z'
+    const end = '2026-06-23T00:00:00Z'
+    const { result } = renderHook(() => useEnergyPrices(start, end), { wrapper: Wrapper })
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+    expect(mockGet).toHaveBeenCalledWith('/api/energy/prices', {
+      params: { query: { start, end } },
+    })
+    expect(result.current.data?.points).toHaveLength(1)
+    expect(result.current.data?.kind).toBe('tibber')
+  })
+
+  it('calls GET /api/energy/prices without params when none provided', async () => {
+    mockGet.mockResolvedValue({
+      data: { kind: 'manual', currency: 'EUR', points: [], tariff: null },
+    })
+
+    const { Wrapper } = makeWrapper()
+    const { useEnergyPrices } = await import('./hooks')
+    const { result } = renderHook(() => useEnergyPrices(), { wrapper: Wrapper })
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+    expect(mockGet).toHaveBeenCalledWith('/api/energy/prices', {
+      params: { query: {} },
+    })
+  })
+})
+
+describe('useEnergyCosts', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls GET /api/energy/costs with start, end, and limit', async () => {
+    mockGet.mockResolvedValue({
+      data: { items: [COST_PERIOD], total: 1 },
+    })
+
+    const { Wrapper } = makeWrapper()
+    const { useEnergyCosts } = await import('./hooks')
+    const start = '2026-06-22T00:00:00Z'
+    const end = '2026-06-23T00:00:00Z'
+    const limit = 100
+    const { result } = renderHook(
+      () => useEnergyCosts(start, end, limit),
+      { wrapper: Wrapper },
+    )
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+    expect(mockGet).toHaveBeenCalledWith('/api/energy/costs', {
+      params: { query: { start, end, limit } },
+    })
+    expect(result.current.data?.items).toHaveLength(1)
+  })
+})
+
+describe('useEnergyCostSummary', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls GET /api/energy/costs/summary with date range', async () => {
+    mockGet.mockResolvedValue({ data: SUMMARY })
+
+    const { Wrapper } = makeWrapper()
+    const { useEnergyCostSummary } = await import('./hooks')
+    const start = '2026-06-01T00:00:00Z'
+    const end = '2026-06-30T23:59:59Z'
+    const { result } = renderHook(
+      () => useEnergyCostSummary(start, end),
+      { wrapper: Wrapper },
+    )
+
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+    expect(mockGet).toHaveBeenCalledWith('/api/energy/costs/summary', {
+      params: { query: { start, end } },
+    })
+    expect(result.current.data?.total_payable).toBe(12.5)
+  })
+})
+
+describe('useRecomputeCosts', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('calls POST /api/energy/costs/recompute and invalidates cost queries', async () => {
+    mockPost.mockResolvedValue({ data: { recomputed: 10 } })
+    // Mock GET for invalidation queries (costs and summary)
+    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
+
+    const { Wrapper } = makeWrapper()
+    const { useRecomputeCosts } = await import('./hooks')
+    const { result } = renderHook(() => useRecomputeCosts(), { wrapper: Wrapper })
+
+    await act(async () => {
+      await result.current.mutateAsync({
+        start: '2026-06-22T00:00:00Z',
+        end: '2026-06-23T00:00:00Z',
+      })
+    })
+
+    expect(mockPost).toHaveBeenCalledWith('/api/energy/costs/recompute', {
+      params: {
+        query: {
+          start: '2026-06-22T00:00:00Z',
+          end: '2026-06-23T00:00:00Z',
+        },
+      },
+    })
+  })
+
+  it('calls POST /api/energy/costs/recompute without params when none provided', async () => {
+    mockPost.mockResolvedValue({ data: { recomputed: 0 } })
+
+    const { Wrapper } = makeWrapper()
+    const { useRecomputeCosts } = await import('./hooks')
+    const { result } = renderHook(() => useRecomputeCosts(), { wrapper: Wrapper })
+
+    await act(async () => {
+      await result.current.mutateAsync({})
+    })
+
+    expect(mockPost).toHaveBeenCalledWith('/api/energy/costs/recompute', {
+      params: { query: {} },
+    })
+  })
+})
--- a/Show More
+++ b/Show More
				`@@ -0,0 +1 @@`
				`"""Modbus integration package — driver, profile loader, and decoder."""`