fix: 增强删除配置时同步服务的停止逻辑

- close() 方法中先设置停止标志
- 强制设置 _sync_in_progress = False
- 确保取消正在运行的自动同步任务

sync_service.py

@@ -556,9 +556,24 @@ class SyncService:
     
     def close(self):
         """Close connections for this data source"""
-        self.stop_auto_sync()
+        # 先设置停止标志，防止新同步开始
+        self._running = False
+        self._sync_in_progress = False
+        
+        # 取消自动同步任务
+        if hasattr(self, '_auto_sync_task') and self._auto_sync_task is not None and not self._auto_sync_task.done():
+            try:
+                self._auto_sync_task.cancel()
+            except Exception as e:
+                logger.error(f"Error cancelling auto sync task: {e}")
+        
+        # 停止当前同步
+        self._sync_in_progress = False
+        
         if hasattr(self.syncer, 'close'):
             self.syncer.close()
+        
+        logger.info(f"Closed all connections for {self.source_name}")
 
 
 class SyncServiceManager: