CavaService improvements

- bring back autosens for better visualization at  low volume input
- enable Cava process as long as we have a visualizer and the sidePanel
is open, this helps capture audio when there is no active mpris player
(ex: mpv, game audio, etc...)

Services/PanelService.qml

@@ -5,5 +5,8 @@ import Quickshell
 Singleton {
   id: root
 
+  // Currently opened panel
   property var openedPanel: null
+
+  property var sidePanel: null
 }