Optimize agent tool async blocking paths

app/agent/tools/impl/query_downloaders.py

@@ -25,11 +25,15 @@ class QueryDownloadersTool(MoviePilotTool):
         """生成友好的提示消息"""
         return "查询下载器配置"
 
+    @staticmethod
+    def _load_downloaders_config():
+        """从内存配置缓存中读取下载器配置。"""
+        return SystemConfigOper().get(SystemConfigKey.Downloaders)
+
     async def run(self, **kwargs) -> str:
         logger.info(f"执行工具: {self.name}")
         try:
-            system_config_oper = SystemConfigOper()
-            downloaders_config = system_config_oper.get(SystemConfigKey.Downloaders)
+            downloaders_config = self._load_downloaders_config()
             if downloaders_config:
                 return json.dumps(downloaders_config, ensure_ascii=False, indent=2)
             return "未配置下载器。"