feat: prevent selection of baby rooms without regular rooms

src/Form/Model/BookingDto.php

@@ -7,6 +7,7 @@ namespace App\Form\Model;
 use App\BusProNet\Constants;
 use App\BusProNet\Model\Booking;
 use App\BusProNet\Model\Travel;
+use App\Validator\Constraints as AppAssert;
 use Symfony\Component\Validator\Constraints as Assert;
 use Symfony\Component\Validator\Context\ExecutionContextInterface;
 
@@ -18,6 +19,7 @@ use Symfony\Component\Validator\Context\ExecutionContextInterface;
  * in participant DTOs regardless of mode, ensuring consistent data structure and
  * simplifying pricing calculations, field handlers, and template rendering.
  */
+#[AppAssert\RoomSelection(groups: ['booking_create_step_1'])]
 class BookingDto
 {
     public const MODE_CREATE = 'create';
@@ -175,17 +177,6 @@ class BookingDto
         return $room?->label;
     }
 
-    #[Assert\Callback(callback: 'validateRoomSelection', groups: ['booking_create_step_1'])]
-    public function validateRoomSelection(ExecutionContextInterface $context): void
-    {
-        $selectedRooms = $this->getSelectedRooms();
-
-        if (0 === count($selectedRooms)) {
-            $context->buildViolation('Bitte mindestens ein Zimmer/Bett auswählen')
-                ->addViolation();
-        }
-    }
-
     #[Assert\Callback]
     public function validateBankAccount(ExecutionContextInterface $context): void
     {