wip: refactor forms

config/services.yaml

@@ -66,3 +66,12 @@ services:
     App\Form\Service\ParticipantRoomChoiceLoaderFactory:
         arguments:
             $choiceListFactory: '@form.choice_list_factory.default'
+
+    # Participant Field Handler Registry with hybrid handler configuration
+    App\Form\ParticipantFieldHandler\ParticipantFieldHandlerRegistry:
+        arguments:
+            $handlers:
+                # Simple handlers (no dependencies) - use class names
+                - 'App\Form\ParticipantFieldHandler\ParticipantAssignedRoomFieldHandler'
+                # Complex handlers (with dependencies) would use service references like:
+                # - '@participant.complex.handler'