feat!: support exponential brightness curve

I don't need most of the fluff for handling other types of displays, and getting rid of it lets me do something a lot nicer: add an exponential-gamma brightness display.

modules/osd/Interactions.qml

@@ -7,10 +7,8 @@ Scope {
     id: root
 
     required property PersistentProperties uiState
-    required property ShellScreen screen
     required property bool hovered
     required property bool suppressed
-    readonly property Brightness.Monitor monitor: Brightness.getMonitorForScreen(screen)
 
     function show(): void {
         if (!root.suppressed) {
@@ -34,7 +32,7 @@ Scope {
     }
 
     Connections {
-        target: root.monitor
+        target: Brightness
 
         function onBrightnessChanged(): void {
             if (root.uiState.osdBrightnessReact)