- Move MonitorTab and TrafficLogTable from proxy/advanced to usage/
- Add Analytics and Monitor tabs to Usage page
- Remove Monitor tab from API Proxy (flatten to 4 tabs)
- Add Model, Input/Output tokens, and Cost columns to traffic log table
- Make log rows clickable with expandable detail panel (JSON body viewer)
- Fix req/min calculation using actual request time span (MIN/MAX timestamps)
- Add word-wrap for large message bodies in expanded view