chore(core/qa): function-audit toolchain + parity/audit reports + pixel-perfect skill

- qa/function-audit: playwright 行为审计工具(audit.mjs/verify-modals.mjs/pages.json)
  + 18 页审计产出(*.audit.md/json、summary、运行日志)
- qa/visual-parity: 调试/测量辅助脚本(_dbg*.mjs/_measure.mjs/_off.mjs)
- core/还原度核对报告.md: 18 页 pixelmatch 核对结果(含 vite 代理陈旧坑记录)
- core/还原与接口待办.md: 逐页还原度/真实数据/交互接入待办总表
- .claude/skills/pixel-perfect-react: 像素级还原 React 的 SKILL 文档
- frontend/public/_devlogin.html: 临时本地登录辅助页(可删)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/qa/function-audit/output/_recheck.log

@@ -0,0 +1,15 @@
+
+[function-audit] products … dead 1 / 25, missing 11
+[function-audit] product-detail … dead 0 / 29, missing 7
+[function-audit] account … dead 2 / 26, missing 5
+
+[function-audit] summary
+┌─────────┬──────────────────┬───────┬───────┬──────┬───────┬─────────┐
+│ (index) │ page             │ total │ works │ dead │ error │ missing │
+├─────────┼──────────────────┼───────┼───────┼──────┼───────┼─────────┤
+│ 0       │ 'products'       │ 25    │ 24    │ 1    │ 0     │ 11      │
+│ 1       │ 'product-detail' │ 29    │ 21    │ 0    │ 0     │ 7       │
+│ 2       │ 'account'        │ 26    │ 21    │ 2    │ 0     │ 5       │
+└─────────┴──────────────────┴───────┴───────┴──────┴───────┴─────────┘
+
+报告:core/qa/function-audit/output/summary.md