fix(edge): LOCAL模式下独立连接云端Redis，确保截图处理器可用

CONFIG_SYNC_MODE=LOCAL 时 config_sync 不初始化云端 Redis，
截图处理器改为独立创建 Redis 连接。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

main.py

@@ -184,7 +184,30 @@ 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
+
             if cloud_redis and self._stream_manager:
                 self._screenshot_handler = ScreenshotHandler(
                     cloud_redis=cloud_redis,
@@ -193,7 +216,7 @@ class EdgeInferenceService:
                 self._screenshot_handler.start()
                 self._logger.info("截图处理器初始化成功")
             else:
-                self._logger.info("截图处理器跳过初始化（云端 Redis 或流管理器不可用）")
+                self._logger.warning("截图处理器跳过初始化（云端 Redis 不可达或流管理器不可用）")
         except Exception as e:
             self._logger.error(f"截图处理器初始化失败: {e}")