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-modules/booking/src/Actions/AssignDriverAction.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Modules\Booking\Actions;
+
+use Modules\Booking\Data\AssignDriverData;
+use Modules\Booking\Enums\BookingStatus;
+use Modules\Booking\Exceptions\DriverAssignmentNotAllowedException;
+use Modules\Booking\Models\Booking;
+
+/**
+ * Driver/vehicle details only make sense once a booking is confirmed
+ * (paid) — dispatch assigns who's actually doing the trip at that point,
+ * not before. Re-running this (e.g. reassigning a different driver) is
+ * allowed as long as the booking is still confirmed.
+ */
+class AssignDriverAction
+{
+    public function handle(Booking $booking, AssignDriverData $data): Booking
+    {
+        if ($booking->status !== BookingStatus::Confirmed) {
+            throw DriverAssignmentNotAllowedException::notConfirmed($booking);
+        }
+
+        $booking->update([
+            'driver_name' => $data->driverName,
+            'driver_phone' => $data->driverPhone,
+            'car_plate_number' => $data->carPlateNumber,
+            'car_model' => $data->carModel,
+        ]);
+
+        return $booking;
+    }
+}