extract OsdSection base component from Volume and Backlight modules

shell/modules/OsdSection.qml

@@ -0,0 +1,25 @@
+import QtQuick
+
+// Base component for bar modules with OSD flash behavior (Volume, Backlight).
+// Panel shows on hover or when flashPanel() is called, auto-dismisses after 1.5s.
+// Modules bind _panelHovered to their HoverPanel's panelHovered property.
+BarSection {
+    id: root
+    tooltip: ""
+
+    property bool _panelHovered: false
+    property bool _osdActive: false
+    readonly property bool _anyHover: root._hovered || _panelHovered
+    readonly property bool _showPanel: _anyHover || _osdActive
+
+    function flashPanel() {
+        _osdActive = true;
+        _osdTimer.restart();
+    }
+
+    Timer {
+        id: _osdTimer
+        interval: 1500
+        onTriggered: root._osdActive = false
+    }
+}