chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/socketio/exceptions.py

@@ -0,0 +1,38 @@
+class SocketIOError(Exception):
+    pass
+
+
+class ConnectionError(SocketIOError):
+    pass
+
+
+class ConnectionRefusedError(ConnectionError):
+    """Connection refused exception.
+
+    This exception can be raised from a connect handler when the connection
+    is not accepted. The positional arguments provided with the exception are
+    returned with the error packet to the client.
+    """
+    def __init__(self, *args):
+        if len(args) == 0:
+            self.error_args = {'message': 'Connection rejected by server'}
+        elif len(args) == 1:
+            self.error_args = {'message': str(args[0])}
+        else:
+            self.error_args = {'message': str(args[0])}
+            if len(args) == 2:
+                self.error_args['data'] = args[1]
+            else:
+                self.error_args['data'] = args[1:]
+
+
+class TimeoutError(SocketIOError):
+    pass
+
+
+class BadNamespaceError(SocketIOError):
+    pass
+
+
+class DisconnectedError(SocketIOError):
+    pass