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/fastapi/security/utils.py

@@ -0,0 +1,10 @@
+from typing import Optional, Tuple
+
+
+def get_authorization_scheme_param(
+    authorization_header_value: Optional[str],
+) -> Tuple[str, str]:
+    if not authorization_header_value:
+        return "", ""
+    scheme, _, param = authorization_header_value.partition(" ")
+    return scheme, param