feat: switch to Beamline combined view while busy

Generalize the robot-mount auto-switch: any busy period now brings up
the combined view so the motion can be watched, and the sample camera
returns when busy clears. Edge-triggered, so manual tab choices
survive between transitions; _mounting renamed to _watching_motion.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/aare/gui/main_window.py

@@ -199,7 +199,7 @@ class MainWindow(QMainWindow):
 
         self._base_url = base_url
         self._token = token
-        self._mounting = False
+        self._watching_motion = False
         self._samcam_feed_banner_active = False
         self._samcam_feed_banner_message = "Sample camera feed unavailable"
 
@@ -2707,11 +2707,16 @@ class MainWindow(QMainWindow):
             if self._remote_close_deadline_ts is not None:
                 self._clear_remote_close_request()
 
-        if not self._mounting and s.state == BeamlineStateEnum.RobotSampleExchange:
-            self._mounting = True
+        # Busy (or the robot station) means something is physically moving:
+        # show the Beamline combined view so the motion can be watched, and
+        # return to the sample camera once it is done. Edge-triggered so a
+        # manual tab choice survives between transitions.
+        moving = bool(s.busy) or s.state == BeamlineStateEnum.RobotSampleExchange
+        if moving and not self._watching_motion:
+            self._watching_motion = True
             self.video_tab.setCurrentWidget(self.beamline_combined_panel)
-        elif self._mounting and s.state != BeamlineStateEnum.RobotSampleExchange:
-            self._mounting = False
+        elif not moving and self._watching_motion:
+            self._watching_motion = False
             self.video_tab.setCurrentWidget(self.sample_camera)
 
     # ========== BATON DIALOG HANDLING ==========