feat: extract booking participant count service

src/Controller/Booking/Create/Step2Controller.php

@@ -9,6 +9,7 @@ use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
 use App\Form\BookingCreateStep2Type;
 use App\Form\Model\BookingDto;
 use App\Service\BookingService;
+use App\Service\BookingParticipantCountService;
 use App\Service\BookingSessionService;
 use App\Service\BookingSummaryDataService;
 use App\Service\ParticipantCardDataService;
@@ -33,6 +34,7 @@ class Step2Controller extends AbstractController
 
     public function __construct(
         private readonly BookingService $bookingService,
+        private readonly BookingParticipantCountService $participantCountService,
         private readonly BookingSessionService $bookingSessionService,
         private readonly BookingSummaryDataService $summaryDataService,
         private readonly TravelDataService $travelDataService,
@@ -64,7 +66,7 @@ class Step2Controller extends AbstractController
         $this->travelDataService->enrichWithFreshAvailabilities($bookingCreateDto->travel);
 
         // Ensure correct number of participants with prepopulation callback
-        $this->bookingService->ensureCorrectNumberOfParticipants(
+        $this->participantCountService->ensureCorrectNumberOfParticipants(
             $bookingCreateDto,
             $this->getUser(),
             fn ($user, $participant) => $this->prepopulationService->prepopulateApplicantFromUser($user, $participant)