- Migration 050: add tariff_id FK to bookings table
- Backend: accept tariff_id in POST/PATCH bookings
- Frontend: load active tariffs in BookingModal, show tariff dropdown
- Price calculation applies tariff modifier (percent or fixed) before discount
- tariffId forwarded through CalendarPage → api.bookings.create/update
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
