功能：area_id 全链路支持 + 截图处理器独立 Redis 连接

- CameraInfo 模型添加 area_id 字段
- SQLite 表增加 area_id 列及迁移
- config_sync 同步 area_id 到本地
- 告警 ext_data 携带 area_id
- 截图处理器使用独立 Redis 连接，避免与配置同步阻塞冲突
- get_all_camera_configs 使用 cursor.description 动态获取列名

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

main.py

@@ -185,29 +185,27 @@ class EdgeInferenceService:
     def _init_screenshot_handler(self):
         """初始化截图处理器"""
         try:
-            # 优先从 config_manager 获取已有的云端 Redis 连接
-            cloud_redis = getattr(self._config_manager, '_cloud_redis', None)
-
-            # LOCAL 模式下 config_manager 不初始化云端 Redis，需要独立创建
-            if cloud_redis is None:
-                try:
-                    import redis
-                    cfg = self._settings.cloud_redis
-                    cloud_redis = redis.Redis(
-                        host=cfg.host,
-                        port=cfg.port,
-                        db=cfg.db,
-                        password=cfg.password,
-                        decode_responses=cfg.decode_responses,
-                        socket_connect_timeout=5,
-                        socket_timeout=5,
-                        retry_on_timeout=True,
-                    )
-                    cloud_redis.ping()
-                    self._logger.info(f"截图处理器独立连接云端 Redis 成功: {cfg.host}:{cfg.port}/{cfg.db}")
-                except Exception as e:
-                    self._logger.warning(f"截图处理器无法连接云端 Redis: {e}")
-                    cloud_redis = None
+            # 截图处理器必须使用独立的 Redis 连接（不能与 config_sync 共用，
+            # 因为两者都做阻塞 XREAD/XREADGROUP，共用连接会互相干扰）
+            cloud_redis = None
+            try:
+                import redis
+                cfg = self._settings.cloud_redis
+                cloud_redis = redis.Redis(
+                    host=cfg.host,
+                    port=cfg.port,
+                    db=cfg.db,
+                    password=cfg.password,
+                    decode_responses=cfg.decode_responses,
+                    socket_connect_timeout=5,
+                    socket_timeout=10,
+                    retry_on_timeout=True,
+                )
+                cloud_redis.ping()
+                self._logger.info(f"截图处理器独立连接云端 Redis 成功: {cfg.host}:{cfg.port}/{cfg.db}")
+            except Exception as e:
+                self._logger.warning(f"截图处理器无法连接云端 Redis: {e}")
+                cloud_redis = None
 
             if cloud_redis and self._stream_manager:
                 self._screenshot_handler = ScreenshotHandler(
@@ -363,7 +361,12 @@ class EdgeInferenceService:
         )
         
         self._logger.info("所有组件初始化完成")
-    
+
+    def _get_camera_area_id(self, camera_id: str) -> Optional[int]:
+        """获取摄像头的 area_id"""
+        cam = self._get_camera_config_by_id(camera_id)
+        return cam.area_id if cam else None
+
     def _get_camera_ids_with_roi(self) -> set:
         """获取有ROI配置的摄像头ID集合
 
@@ -844,6 +847,7 @@ class EdgeInferenceService:
                         "edge_node_id": self._settings.mqtt.device_id,
                         "first_frame_time": first_frame_time,
                         "vehicle_count": alert.get("vehicle_count"),
+                        "area_id": self._get_camera_area_id(camera_id),
                     },
                 )
                 self._reporter.report_alarm(alarm_info, screenshot=frame.image)