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.

tests/test_crawler/test_base.py

@@ -1,5 +1,7 @@
-import pytest
 from datetime import datetime
+
+import pytest
+
 from app.crawler.base import BaseSpider, CrawlResult, PipelineConfig, PipelineResult