wip: backport booking create flow form handling to edit flow

src/Form/Model/BookingEditDto.php

@@ -60,6 +60,10 @@ class BookingEditDto implements BookingDtoInterface
             $pickup = $booking->getPickupForParticipant($index);
             $participantData->pickup = $pickup;
 
+            // Room assignment - extract from booking room mappings
+            $room = $booking->getRoomForParticipant($index);
+            $participantData->assignedRoomId = $room?->id;
+
             $instance->participants[$index] = $participantData;
         }