feat(poll): enforce governed participation ownership

tests/test_service.py

@@ -22,6 +22,7 @@ from govoplan_poll.backend.service import (
     create_poll,
     create_poll_invitation,
     open_poll,
+    poll_owner_ref,
     poll_result_summary_by_id,
     submit_poll_response,
     submit_poll_response_with_token,
@@ -172,6 +173,11 @@ class PollServiceTests(unittest.TestCase):
                 ],
                 options=[PollOptionInput(key="slot-1", label="Monday")],
             ),
+            mutation_owner=poll_owner_ref(
+                module_id="scheduling",
+                resource_type="scheduling_request",
+                resource_id="request-1",
+            ),
         )
 
         self.assertEqual(poll.context_module, "scheduling")