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/lexers/functional.py

@@ -0,0 +1,21 @@
+"""
+    pygments.lexers.functional
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Just export lexer classes previously contained in this module.
+
+    :copyright: Copyright 2006-2025 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+# ruff: noqa: F401
+from pygments.lexers.lisp import SchemeLexer, CommonLispLexer, RacketLexer, \
+    NewLispLexer, ShenLexer
+from pygments.lexers.haskell import HaskellLexer, LiterateHaskellLexer, \
+    KokaLexer
+from pygments.lexers.theorem import CoqLexer
+from pygments.lexers.erlang import ErlangLexer, ErlangShellLexer, \
+    ElixirConsoleLexer, ElixirLexer
+from pygments.lexers.ml import SMLLexer, OcamlLexer, OpaLexer
+
+__all__ = []