feat: AI SQL Trace - HITL + Chart.js + StarRocks-optimized prompt

- HITL: Accept/Reject SQL before execution
- Chart.js: Auto-detect data shape -> render number cards/bar/doughnut/line
- Prompt: Verified StarRocks partition pruning rules (no DATE() on column)
- Summary: Agent provides 2-3 sentence Vietnamese explanation of results
- Fix: renderTraceDocument -> renderDataResults for history loading
- Auth: Login/admin pages, middleware, JWT auth
- Report Agent: Full report generation system
- New pages: stress-test, regression-test, user-simulator, competitor-research