feat(bar): add audio indicator widget

services/Audio.qml

@@ -0,0 +1,24 @@
+pragma Singleton
+
+import QtQuick
+import Quickshell
+import Quickshell.Services.Pipewire
+
+Singleton {
+    id: root
+
+    readonly property string outputName: root.displayName(Pipewire.defaultAudioSink)
+    readonly property string inputName: root.displayName(Pipewire.defaultAudioSource)
+    readonly property url outputIcon: `${Quickshell.shellPath("assets")}/icons/speaker.svg`
+    readonly property url inputIcon: `${Quickshell.shellPath("assets")}/icons/microphone.svg`
+
+    function displayName(node: PwNode): string {
+        if (!node)
+            return "none";
+        return node.description || node.name;
+    }
+
+    PwObjectTracker {
+        objects: [Pipewire.defaultAudioSink, Pipewire.defaultAudioSource]
+    }
+}