Add local-network deployment automation and tighten runtime defaults

This commit adds the first complete local-network deployment path for the project. It normalizes the runtime contract around a fixed container listener on 0.0.0.0:10000, binds the published compose port to 127.0.0.1, and keeps the image/build workflow aligned with the released container image.

It also introduces an installation script, an nginx reverse-proxy template, and a safer SQLite backup flow based on sqlite3 .backup with retention and optional rclone upload support. Deployment-oriented configuration has been consolidated into .env.example, repository-local .env files are now ignored, and the deployment scripts are executable.

In addition, the frontend mixed-content issue is fixed by switching the stylesheet reference to a root-relative static path, with tests updated to cover the regression. README guidance has been expanded to document the new install, nginx, backup, and restore conventions.

scripts/backup_db.sh

@@ -1,27 +1,83 @@
 #!/usr/bin/env sh
 set -eu
 
-PROJECT_ROOT=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
-cd "$PROJECT_ROOT"
+APP_DIR="__APP_DIR__"
+DEFAULT_BACKUP_DIR="__BACKUP_DIR__"
+ENV_FILE="$APP_DIR/.env"
 
-if [ ! -f ".env" ] && [ -f ".env.example" ]; then
-  echo "未找到 .env，先从 .env.example 复制一份："
-  echo "  cp .env.example .env"
+require_command() {
+  if ! command -v "$1" >/dev/null 2>&1; then
+    echo "Missing required command: $1" >&2
+    exit 1
+  fi
+}
+
+resolve_path() {
+  case "$1" in
+    /*) printf '%s\n' "$1" ;;
+    *) printf '%s/%s\n' "$APP_DIR" "$1" ;;
+  esac
+}
+
+if [ ! -f "$ENV_FILE" ]; then
+  echo "Deployed .env file not found: $ENV_FILE" >&2
   exit 1
 fi
 
-DATA_DIR_VALUE=$(grep '^DATA_DIR=' .env 2>/dev/null | tail -n 1 | cut -d '=' -f 2- || true)
-DATA_DIR=${DATA_DIR_VALUE:-./data}
-DB_PATH="$DATA_DIR/app.db"
+set -a
+. "$ENV_FILE"
+set +a
+
+require_command sqlite3
+
+if [ -n "${BACKUP_REMOTE:-}" ]; then
+  require_command rclone
+fi
+
+BACKUP_DIR=${BACKUP_DIR:-$DEFAULT_BACKUP_DIR}
+DATA_DIR=${DATA_DIR:-./data}
+DB_PATH="$(resolve_path "$DATA_DIR")/app.db"
 
 if [ ! -f "$DB_PATH" ]; then
-  echo "未找到数据库文件：$DB_PATH"
+  echo "Database file not found: $DB_PATH" >&2
   exit 1
 fi
 
-mkdir -p backups
+mkdir -p "$BACKUP_DIR"
 TIMESTAMP=$(date +"%Y%m%d-%H%M%S")
-DESTINATION="backups/app-$TIMESTAMP.db"
+TMP_BACKUP="$BACKUP_DIR/.app-$TIMESTAMP.db.tmp"
+FINAL_BACKUP="$BACKUP_DIR/app-$TIMESTAMP.db"
 
-cp "$DB_PATH" "$DESTINATION"
-echo "备份已创建：$DESTINATION"
+cleanup() {
+  rm -f "$TMP_BACKUP"
+}
+
+trap cleanup EXIT INT TERM
+
+# Prefer sqlite3 .backup so the snapshot stays transactionally consistent without
+# stopping the running container or racing with SQLite writes.
+sqlite3 "$DB_PATH" <<EOF
+.timeout 5000
+.backup $TMP_BACKUP
+EOF
+
+mv "$TMP_BACKUP" "$FINAL_BACKUP"
+trap - EXIT INT TERM
+
+count=0
+for backup_file in $(find "$BACKUP_DIR" -maxdepth 1 -type f -name 'app-*.db' | sort -r); do
+  count=$((count + 1))
+  if [ "$count" -gt 5 ]; then
+    rm -f "$backup_file"
+  fi
+done
+
+if [ -n "${BACKUP_REMOTE:-}" ]; then
+  remote_target=${BACKUP_REMOTE%/}/$(basename "$FINAL_BACKUP")
+  rclone copyto "$FINAL_BACKUP" "$remote_target"
+  echo "Backup uploaded to remote: $remote_target"
+else
+  echo "BACKUP_REMOTE is empty; skipping remote upload"
+fi
+
+echo "Backup created: $FINAL_BACKUP"