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/pygments/styles/staroffice.py

@@ -0,0 +1,31 @@
+"""
+    pygments.styles.staroffice
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Style similar to StarOffice style, also in OpenOffice and LibreOffice.
+
+    :copyright: Copyright 2006-2025 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from pygments.style import Style
+from pygments.token import Comment, Error, Literal, Name, Token
+
+
+__all__ = ['StarofficeStyle']
+
+
+class StarofficeStyle(Style):
+    """
+    Style similar to StarOffice style, also in OpenOffice and LibreOffice.
+    """
+    name = 'staroffice'
+
+    
+    styles = {
+        Token:                  '#000080',   # Blue
+        Comment:                '#696969',   # DimGray
+        Error:                  '#800000',   # Maroon
+        Literal:                '#EE0000',   # Red
+        Name:                   '#008000',   # Green
+    }