Add Booking module: model, create/read/cancel API, Filament resource (T4.1-T4.7)

- Booking model with booking_vehicle_options line items (supports mixing
  vehicle options like front_seat + back_seat in one booking), price
  snapshot, status machine, and driver/car assignment fields
- BookingService: front-seat max, disabled-option toggles, duplicate-option
  and whole-vehicle-exclusivity guards
- CreateBookingAction, CancelBookingAction, AssignDriverAction
- BookingRefGenerator: sequential EVB-AAAAA1-style refs via row lock
- POST/GET/cancel booking API endpoints (Sanctum, ownership + admin policy)
- BookingPlugin + Filament BookingResource: list, detail view, Cancel and
  Assign Driver actions (shared between table and detail page)
- domain.md updated for multi-vehicle-option bookings (§2) and driver/
  vehicle assignment (§5a)

CLAUDE.md

@@ -163,3 +163,8 @@ This project has domain-specific skills available in `**/skills/**`. You MUST ac
 - This application runs inside Docker via Laravel Sail. Use `./vendor/bin/sail artisan ...` instead of `php artisan ...`, and `./vendor/bin/sail composer ...` instead of `composer ...`.
 - For binaries not wrapped by Sail's own commands (e.g. Pint), run them inside the container: `./vendor/bin/sail exec laravel.test vendor/bin/pint --dirty --format agent`.
 - Check containers are up first with `./vendor/bin/sail ps` before running commands; start them with `./vendor/bin/sail up -d` if they aren't.
+
+## Architecture / ERD Diagram
+
+- The canonical tldraw board for this project's architecture and ERD lives at `/home/marcspecta/Documents/EV Booking System Architecture.tldraw` (outside the repo — not committed). Use this path when opening/updating the board with the tldraw-offline skill/agent.
+- Do not copy or save this file into the project directory; a stray copy there was previously deleted.