- Backend: trace.Logger ring-buffer for request chain events
- Backend: perf.Monitor with runtime.MemStats sampling every 10s
- Backend: /api/v1/admin/trace and /api/v1/admin/perf endpoints
- Frontend: TracePage — timeline with hop icons and status dots
- Frontend: PerformancePage — memory/GC bar charts + live stats
- Admin nav expanded to 11 items