wip: improved validation and feedback

src/Form/Model/BookingDto.php

@@ -196,7 +196,7 @@ class BookingDto
         }
     }
 
-    #[Assert\Callback(groups: ['booking_create_step_2', 'booking_edit'])]
+    #[Assert\Callback(groups: ['booking_create', 'booking_edit'])]
     public function validateEmailUniqueness(ExecutionContextInterface $context): void
     {
         // Build map of email addresses to participant indices (adults only)