Bar widgets: modular loading refactoring via BarWidgetRegistry+NWidgetLoader

- Hot reload is working again.
- Should also be more memory efficient on multi monitors.

Services/PanelService.qml

@@ -1,23 +1,38 @@
 pragma Singleton
 
 import Quickshell
+import qs.Commons
 
 Singleton {
   id: root
 
-  // A ref. to the sidePanel, so it's accessible from other services
-  property var sidePanel: null
-
-  // A ref. to the lockScreen, so it's accessible from other services
+  // A ref. to the lockScreen, so it's accessible from anywhere
+  // This is not a panel...
   property var lockScreen: null
 
-  // A ref. to the updatePanel, so it's accessible from other services
-  property var updatePanel: null
-
   // Currently opened panel
   property var openedPanel: null
 
-  function registerOpen(panel) {
+  property var registeredPanels: ({})
+
+  // Register this panel
+  function registerPanel(panel) {
+    registeredPanels[panel.objectName] = panel
+    Logger.log("PanelService", "Registered:", panel.objectName)
+  }
+
+  // Returns a panel
+  function getPanel(name) {
+    return registeredPanels[name] || null
+  }
+
+  // Check if a panel exists
+  function hasPanel(name) {
+    return name in registeredPanels
+  }
+
+  // Helper to keep only one panel open at any time
+  function willOpenPanel(panel) {
     if (openedPanel && openedPanel != panel) {
       openedPanel.close()
     }