Multi-iPad dest_id routing, activity ring, context menu hide, live label/visibility sync

Desktop:
- Replace Remote checkbox with T: dest_spin (0=Off, 1-9=tablet) on all widgets
- dest_id persisted in get_state/set_state, broadcast in tablet snapshot
- dest_spin.valueChanged triggers save + broadcast to iPad
- _on_widget_visibility_from_tablet updates dest_spin from iPad hide event
- _broadcast_preset_update shared helper; ws_server.has_clients guard
- label editingFinished triggers live label sync to iPad

iOS:
- VC-Arrange/VC-Logging/Widgets-Reusable-UI file reorganisation
- ArrangeObjects/ArrangeView rename, 7-bucket Arrange-Functions split
- myTabletId (UserDefaults) + tabletIdField next to port in toolbar
- Preset filter: destId == myTabletId instead of visible bool
- BaseWidget activity ring: long press gesture (touch) + final update() flash
- Context menu long press (arrange mode): hide widget, save layout, send dest_id:0
- Same-UUID preset check skips Preset Switched alert on visibility/label updates
- autoSwitchEnabled, toolbarStatusLabel, presetLabel, statusToken

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/ws_server.py

@@ -7,6 +7,7 @@ from PyQt6.QtNetwork import QHostAddress
 class WSServer(QObject):
     control_received = pyqtSignal(str, int)
     layout_saved = pyqtSignal(str, object)
+    widget_visibility_received = pyqtSignal(str, int)
     client_connected = pyqtSignal()
     log_signal = pyqtSignal(str)
     raw_in_signal = pyqtSignal(str)
@@ -51,11 +52,20 @@ class WSServer(QObject):
                 n = len(data.get("layout", {}))
                 self.log_signal.emit(f"layout saved  preset={data['preset_uuid'][:8]}…  {n} widgets")
                 self.layout_saved.emit(data["preset_uuid"], data["layout"])
+            elif ev == "widget_visibility":
+                uid = data["uid"]
+                dest_id = int(data.get("dest_id", 0))
+                self.log_signal.emit(f"widget visibility  uid={uid[:8]}…  dest_id={dest_id}")
+                self.widget_visibility_received.emit(uid, dest_id)
             else:
                 self.log_signal.emit(f"unknown event: {ev}")
         except Exception as e:
             self.log_signal.emit(f"bad message: {e}")
 
+    @property
+    def has_clients(self) -> bool:
+        return len(self._clients) > 0
+
     def broadcast(self, data: dict):
         if not self._clients:
             return