fix: properly handle 'veg' services in booking edit flow

src/Service/BookingEditDraftMerger.php

@@ -209,6 +209,14 @@ class BookingEditDraftMerger
                 $participant->board = $this->resolveServiceArray($data['board'], $travel->additionalServices);
             }
 
+            // Veg (single service) - merge strategy: only apply if resolves to valid service
+            if (true === array_key_exists('veg', $data) && null !== $data['veg']) {
+                $resolved = $this->resolveService($data['veg'], $travel->additionalServices);
+                if (null !== $resolved) {
+                    $participant->veg = $resolved;
+                }
+            }
+
             // Rentals (array) - overwrite strategy: user can deselect all
             if (true === array_key_exists('rentals', $data) && true === is_array($data['rentals'])) {
                 $participant->rentals = $this->resolveServiceArray($data['rentals'], $travel->additionalServices);