fix: harden conversational mode draft revisions

tests/e2e/test_assistant_web_api.py

@@ -770,6 +770,37 @@ class TestCodexAssistantWebApi:
         assert action["payload"]["hardware_execution_allowed"] is False
         assert events[0]["engine"] == "n7web-mode-builder"
 
+    def test_become_percentage_update_keeps_movie_draft_route_end_to_end(
+        self,
+    ) -> None:
+        reference = {
+            "name": "观影模式",
+            "source_request_id": "req-mode-preview",
+            "vehicle_id": "denza_n7",
+        }
+        message = "把观影模式的遮阳帘变成100%"
+
+        events = self.post_assistant(
+            {
+                "message": message,
+                "conversation_id": "conv-api-movie-shade-become-percent",
+                "execution_mode": "hardware",
+                "mode_profile_draft_context": reference,
+            }
+        )
+
+        assert not FAKE_CODEX.turn_calls
+        call = AssistantApiHandler.service.calls[-1]
+        assert call["utterance"] == message
+        assert call["mode_profile_draft_context"] == reference
+        action = next(event for event in events if event["type"] == "action.completed")
+        assert action["success"] is True
+        assert action["payload"]["execution_mode"] == "dry_run"
+        assert action["payload"]["hardware_execution_allowed"] is False
+        assert action["payload"]["mode_profile_draft"]["draft_revision"] == 2
+        assert events[0]["route"] == "vehicle_control"
+        assert events[0]["engine"] == "n7web-mode-builder"
+
     def test_active_draft_reference_is_not_forwarded_for_an_unrelated_question(
         self,
     ) -> None: