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/zipp/compat/py310.py

@@ -0,0 +1,13 @@
+import io
+import sys
+
+
+def _text_encoding(encoding, stacklevel=2, /):  # pragma: no cover
+    return encoding
+
+
+text_encoding = (
+    io.text_encoding  # type: ignore[unused-ignore, attr-defined]
+    if sys.version_info > (3, 10)
+    else _text_encoding
+)