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/rich/pager.py

@@ -0,0 +1,34 @@
+from abc import ABC, abstractmethod
+from typing import Any
+
+
+class Pager(ABC):
+    """Base class for a pager."""
+
+    @abstractmethod
+    def show(self, content: str) -> None:
+        """Show content in pager.
+
+        Args:
+            content (str): Content to be displayed.
+        """
+
+
+class SystemPager(Pager):
+    """Uses the pager installed on the system."""
+
+    def _pager(self, content: str) -> Any:  #  pragma: no cover
+        return __import__("pydoc").pager(content)
+
+    def show(self, content: str) -> None:
+        """Use the same pager used by pydoc."""
+        self._pager(content)
+
+
+if __name__ == "__main__":  # pragma: no cover
+    from .__main__ import make_test_card
+    from .console import Console
+
+    console = Console()
+    with console.pager(styles=True):
+        console.print(make_test_card())