Give Sound the whole story, and keep the buttons inside the card

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/modules/quicksettings/AudioSlider.qml

@@ -25,6 +25,10 @@ Item {
     readonly property real volume: root.node && root.node.audio ? root.node.audio.volume : 0
     readonly property bool muted: root.node && root.node.audio ? root.node.audio.muted : false
 
+    // Over-amplification extends the output to 150%. The input is never
+    // extended: a microphone above 100% is gain on noise, not loudness.
+    readonly property real maximum: root.output && Settings.overAmplification ? 1.5 : 1
+
     PwObjectTracker {
         objects: root.node ? [root.node] : []
     }
@@ -57,21 +61,46 @@ Item {
     }
 
     ValueSlider {
+        id: slider
         anchors.left: muteButton.right
         anchors.leftMargin: 6
         anchors.right: chevron.left
         anchors.rightMargin: 4
         anchors.verticalCenter: parent.verticalCenter
-        value: root.muted ? 0 : root.volume
+        value: root.muted ? 0 : root.volume / root.maximum
         onMoved: v => {
             if (!root.node || !root.node.audio)
                 return;
             // Nudging the slider is also how you unmute, same as GNOME.
             root.node.audio.muted = false;
-            root.node.audio.volume = v;
+            root.node.audio.volume = v * root.maximum;
         }
     }
 
+    // Everything above 100%, marked over the track so the loud end of the
+    // slider is visibly the loud end rather than more of the same.
+    Rectangle {
+        anchors.right: slider.right
+        anchors.verticalCenter: slider.verticalCenter
+        width: root.maximum > 1 ? slider.width * (1 - 1 / root.maximum) : 0
+        height: 10
+        radius: 2
+        visible: root.maximum > 1
+        color: Theme.alpha(Theme.warn, 0.30)
+        border.width: 0
+    }
+
+    Rectangle {
+        anchors.verticalCenter: slider.verticalCenter
+        x: slider.x + slider.width / root.maximum - 1
+        width: 2
+        height: 16
+        radius: 1
+        visible: root.maximum > 1
+        color: Theme.alpha(Theme.warn, 0.7)
+        border.width: 0
+    }
+
     IconButton {
         id: chevron
         anchors.right: parent.right