NightLight: refactored the code to make simpler

- using intensity instead of warmth
- animated color transition
- removed unecessary bindings and double properties
- using better icons to avoid confusion with brightness
- polished settings UI

Modules/NightLight/NightLightOverlay.qml

@@ -0,0 +1,46 @@
+import QtQuick
+import Quickshell
+import Quickshell.Wayland
+import qs.Commons
+import qs.Services
+
+Variants {
+  model: Quickshell.screens
+
+  delegate: Loader {
+    required property ShellScreen modelData
+    readonly property real scaling: ScalingService.scale(modelData)
+
+    active: NightLightService.isActive
+
+    sourceComponent: PanelWindow {
+      screen: modelData
+      color: Color.transparent
+      anchors {
+        top: true
+        bottom: true
+        left: true
+        right: true
+      }
+
+      // Ensure a full click through
+      mask: Region {}
+
+      WlrLayershell.layer: WlrLayershell.Overlay
+      WlrLayershell.exclusionMode: ExclusionMode.Ignore
+      WlrLayershell.keyboardFocus: WlrKeyboardFocus.None
+      WlrLayershell.namespace: "noctalia-nightlight"
+
+      Rectangle {
+        anchors.fill: parent
+        color: NightLightService.overlayColor
+
+        Behavior on color {
+          ColorAnimation {
+            duration: Style.animationSlow
+          }
+        }
+      }
+    }
+  }
+}