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/aioitertools/helpers.py

@@ -0,0 +1,21 @@
+# Copyright 2022 Amethyst Reese
+# Licensed under the MIT license
+
+import inspect
+from collections.abc import Awaitable
+
+from typing import Protocol, Union
+
+from .types import T
+
+
+class Orderable(Protocol):  # pragma: no cover
+    def __lt__(self, other): ...
+
+    def __gt__(self, other): ...
+
+
+async def maybe_await(object: Union[Awaitable[T], T]) -> T:
+    if inspect.isawaitable(object):
+        return await object  # type: ignore
+    return object  # type: ignore