feat: add smart flight tracking with AviationStack API + visual progress
- Add 20+ flight fields (terminal, gate, delays, estimated times, etc.)
- Smart polling cron with budget-aware priority queue (100 req/month)
- Tracking phases: FAR_OUT → PRE_DEPARTURE → ACTIVE → LANDED
- Visual FlightProgressBar with animated airplane between airports
- FlightCard with status dots, delay badges, expandable details
- FlightList rewrite: card-based, grouped by status, search/filter
- Dashboard: enriched flight status widget with compact progress bars
- CommandCenter: flight alerts + enriched arrivals with gate/terminal
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>