volume: reduce scroll sensitivity

Use 2% steps and accumulate wheel deltas so high-res/inertial scrolling
steps once per notch instead of firing per micro-event.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

widgets/Volume.qml

@@ -17,11 +17,20 @@ MouseArea {
     cursorShape: Qt.PointingHandCursor
     acceptedButtons: Qt.LeftButton
 
+    // accumulate raw wheel deltas so high-res / inertial scrolling doesn't
+    // fire a full step per micro-event; one notch (120 units) == one step
+    property real _wheelAccum: 0
+    readonly property real _wheelStep: 0.02
+
     onClicked: { if (audio) audio.muted = !audio.muted; }
     onWheel: wheel => {
         if (!audio) return;
+        _wheelAccum += wheel.angleDelta.y;
+        const notches = Math.trunc(_wheelAccum / 120);
+        if (notches === 0) return;
+        _wheelAccum -= notches * 120;
         audio.volume = Math.max(0, Math.min(1,
-            audio.volume + (wheel.angleDelta.y > 0 ? 0.05 : -0.05)));
+            audio.volume + notches * _wheelStep));
     }
 
     // keep the sink's audio properties live