Remove daily report system (page, API routes, cron scheduler) as it is
no longer needed. Add /api/metrics endpoint exposing total and time-
windowed counts (27h, 7d, 30d) for users, workspaces, projects, repos,
rooms, and skills.
Also clean up dead code:
- Remove OpenRouter sync and alerts check routes
- Remove syncModels/checkAlerts from adminrpc client
- Remove unused adminRpcAvailable state from platform sessions page
- Fix handleEdit displayName comparison bug in platform users page
- Simplify pricing sync to create 0-price defaults
