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/build/_exceptions.py

@@ -0,0 +1,65 @@
+from __future__ import annotations
+
+import subprocess
+import types
+
+
+class BuildException(Exception):
+    """
+    Exception raised by :class:`build.ProjectBuilder`.
+    """
+
+
+class BuildBackendException(Exception):
+    """
+    Exception raised when a backend operation fails.
+    """
+
+    def __init__(
+        self,
+        exception: Exception,
+        description: str | None = None,
+        exc_info: tuple[type[BaseException], BaseException, types.TracebackType] | tuple[None, None, None] = (
+            None,
+            None,
+            None,
+        ),
+    ) -> None:
+        super().__init__()
+        self.exception = exception
+        self.exc_info = exc_info
+        self._description = description
+
+    def __str__(self) -> str:
+        if self._description:
+            return self._description
+        return f'Backend operation failed: {self.exception!r}'
+
+
+class BuildSystemTableValidationError(BuildException):
+    """
+    Exception raised when the ``[build-system]`` table in pyproject.toml is invalid.
+    """
+
+    def __str__(self) -> str:
+        return f'Failed to validate `build-system` in pyproject.toml: {self.args[0]}'
+
+
+class FailedProcessError(Exception):
+    """
+    Exception raised when a setup or preparation operation fails.
+    """
+
+    def __init__(self, exception: subprocess.CalledProcessError, description: str) -> None:
+        super().__init__()
+        self.exception = exception
+        self._description = description
+
+    def __str__(self) -> str:
+        return self._description
+
+
+class TypoWarning(Warning):
+    """
+    Warning raised when a possible typo is found.
+    """