feat: basic themes for event sites

src/Controller/Booking/Create/IndexController.php

@@ -72,6 +72,9 @@ class IndexController extends AbstractController
             // Store optional return URL in session (defaults to main EP site)
             $this->bookingService->storeReturnUrl($request, $params->returnUrl);
 
+            // Store theme for consistent styling throughout the booking flow
+            $this->bookingService->storeTheme($request, $params->theme);
+
             // Create fresh booking session with the provided parameters
             $bookingDto = $this->bookingService->startFreshBooking($request, $dateId, $hotelId, $agencyId);