feat: notify vehicle of published firmware

src/cognitive_agent/application/seat_service.py

@@ -1807,6 +1807,14 @@ class SeatDemoService(ModeScheduleServiceMixin):
 
         return self._vehicle_mqtt_transport.publish_extension_toy_message(payload)
 
+    def publish_firmware_notification(
+        self,
+        payload: Mapping[str, Any],
+    ) -> dict[str, Any]:
+        """Publish one firmware release notification through the vehicle broker."""
+
+        return self._vehicle_mqtt_transport.publish_firmware_notification(payload)
+
     def set_extension_control_handler(
         self,
         handler: Callable[[bytes], None] | None,