chore: ruff 代码检查与修复

130 issues auto-fixed (import ordering, UP045/UP006 type annotations),
33 issues manually fixed (E712/E501/E402/E722 + N818 rename + per-file
wechat ignore for N8xx naming conventions). All 33 tests pass.

pyproject.toml

@@ -36,6 +36,9 @@ line-length = 100
 [tool.ruff.lint]
 select = ["E", "F", "I", "N", "W", "UP"]
 
+[tool.ruff.lint.per-file-ignores]
+"app/wechat/*.py" = ["N802", "N803", "N806"]
+
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 testpaths = ["tests"]