- Exempt /api/config/auth, /api/config/features, /health, /metrics from rate limiting
- Fix generic exception handler to return proper JSON for HTTPException instead of re-raising
- Add startup log with auth_enabled and version
- Add frontend console logging for auth config fetch errors
- Show 'Auth: OFF' or 'Auth: misconfigured' on auth button instead of empty text
- Add backend debug logging to /api/config/auth endpoint