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/numpy/linalg/linalg.py

@@ -0,0 +1,17 @@
+def __getattr__(attr_name):
+    import warnings
+
+    from numpy.linalg import _linalg
+    ret = getattr(_linalg, attr_name, None)
+    if ret is None:
+        raise AttributeError(
+            f"module 'numpy.linalg.linalg' has no attribute {attr_name}")
+    warnings.warn(
+        "The numpy.linalg.linalg has been made private and renamed to "
+        "numpy.linalg._linalg. All public functions exported by it are "
+        f"available from numpy.linalg. Please use numpy.linalg.{attr_name} "
+        "instead.",
+        DeprecationWarning,
+        stacklevel=3
+    )
+    return ret