30994dafb2
- Added `/api/stats/providers` endpoint and database queries returning per-provider request/token/cost totals, hourly burn, and time-series data. - Created ProvidersRoute UI component with totals panel, trend charts, peak-hours histogram, and window-insights visualizations. - Added usage-window analytics computing peak utilization fractions, ideal account counts, and exhaustion events from usage snapshots. - Included comprehensive tests for the aggregation logic, API, and window-stat computations.