Add object calibration

python_app/gui/app_window.py

@@ -791,6 +791,9 @@ class AppWindow(
             # 0) Stop the GPIO button watcher so a late press cannot start work.
             self._stop_control_button_watcher()
             self._resume_pipeline_after_capture = False
+            controller = getattr(self, "_object_calibration_controller", None)
+            if controller is not None:
+                controller.shutdown()
             # 0) Drop the B-scan replay writer so a pending debounce cannot push into a
             # ring we are about to tear down.
             self._bscan_reprocess_timer.stop()