fix: swallow first pipewire/backlight value to prevent osd on startup

modules/Backlight.qml

@@ -12,13 +12,17 @@ M.BarSection {
 
     property int percent: 0
     property bool _osdActive: false
-    property bool _ready: false
+    property bool _percentInit: false
     readonly property bool _showPanel: root._hovered || hoverPanel.panelHovered || _osdActive
 
-    Component.onCompleted: _ready = true
-
-    onPercentChanged: if (_ready && percent > 0)
-        _flashPanel()
+    onPercentChanged: {
+        if (!_percentInit) {
+            _percentInit = true;
+            return;
+        }
+        if (percent > 0)
+            _flashPanel();
+    }
 
     function _flashPanel() {
         _osdActive = true;