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)

app/Providers/Filament/AdminPanelProvider.php

@@ -19,6 +19,7 @@ use Illuminate\Foundation\Http\Middleware\PreventRequestForgery;
 use Illuminate\Routing\Middleware\SubstituteBindings;
 use Illuminate\Session\Middleware\StartSession;
 use Illuminate\View\Middleware\ShareErrorsFromSession;
+use Modules\Booking\BookingPlugin;
 use Modules\Catalog\CatalogPlugin;
 use Modules\Routing\RoutingPlugin;
 
@@ -43,6 +44,7 @@ class AdminPanelProvider extends PanelProvider
             ->plugins([
                 CatalogPlugin::make(),
                 RoutingPlugin::make(),
+                BookingPlugin::make(),
             ])
             ->discoverResources(in: app_path('Filament/Resources'), for: 'App\Filament\Resources')
             ->discoverPages(in: app_path('Filament/Pages'), for: 'App\Filament\Pages')