M5-T06: add Energy device management UI and sidebar entry

frontend/src/components/AppSidebar.test.tsx

@@ -1,15 +1,16 @@
 /**
- * Tests for AppSidebar (M5-T01).
+ * 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 three nav items render (Home, Records, Config).
+ * 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'
@@ -76,10 +77,11 @@ describe('AppSidebar', () => {
   // 1. All nav items render
   // -------------------------------------------------------------------------
 
-  it('renders Home, Records, and Config nav items', () => {
+  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()
   })
 
@@ -123,4 +125,14 @@ describe('AppSidebar', () => {
     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')
+  })
 })

frontend/src/components/AppSidebar.tsx

@@ -1,18 +1,16 @@
 /**
  * AppSidebar — vertical sidebar navigation for all protected pages.
  *
- * Nav items: Home / Records / Config
+ * 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).
- *
- * NOTE: Energy nav item is intentionally absent — added in M5-T06 once /energy exists.
  */
 
 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 } from 'react-feather'
+import { Home, List, Settings, Sun, Moon, LogOut, Zap } from 'react-feather'
 import { useQueryClient } from '@tanstack/react-query'
 import apiClient from '../api/client'
 
@@ -40,6 +38,12 @@ const NAV_ENTRIES: NavEntry[] = [
     icon: <List size={18} />,
     testId: 'nav-records',
   },
+  {
+    to: '/energy',
+    label: 'Energy',
+    icon: <Zap size={18} />,
+    testId: 'nav-energy',
+  },
   {
     to: '/config',
     label: 'Config',