test: cover null venue SOR normalization

tests/application/test_venue_intent_flow.py

@@ -121,7 +121,10 @@ def test_invalid_venue_is_rejected_before_slot_transition(invalid_venue: str) ->
     assert repo.list_slots("default")[0].status is SlotState.INACTIVE
 
 
-def test_omitted_wire_venue_remains_sor_for_cancel_and_restart() -> None:
+@pytest.mark.parametrize("venue_field", [{}, {"venue": None}], ids=["omitted", "null"])
+def test_missing_wire_venue_remains_sor_for_cancel_and_restart(
+    venue_field: dict[str, object],
+) -> None:
     repo = InMemorySlotRepository()
     service = SlotService(repo)
     intents = IntentService(
@@ -142,6 +145,7 @@ def test_omitted_wire_venue_remains_sor_for_cancel_and_restart() -> None:
                 "intent_id": "auto-buy",
                 "portfolio_id": "PF-1",
                 "qty": 1,
+                **venue_field,
             },
             correlation_id="auto-buy",
         )