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/fft/helper.py

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