Mute both channels from the audio hero, one from each slider

The hero switch is the panel's on/off, so it now carries output and input
together rather than output alone. It reads as on while anything is still
audible, which keeps muting a single channel from flipping the master switch.
Right-clicking a volume bar mutes just that channel -- output, input, or one
app's stream -- matching what the `m` key already does for the focused row.

Only channels that exist get a vote: a machine with no default source would
otherwise report its input unmuted forever, leaving the switch able to mute but
never to unmute.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

shell/plugins/panels/audio/Panel.qml

@@ -165,7 +165,13 @@ Panel {
   // "header" is a virtual section for the hero output mute toggle; it sits
   // above the output section so the speaker can be muted from the keyboard.
   readonly property bool headerHasCursor: cursorActive && focusSection === "header"
-  readonly property string toggleHint: root.outputMuted ? "Unmute output" : "Mute output"
+  // Only channels that actually exist get a vote. A box with no default source
+  // would otherwise report "input unmuted" forever, leaving the hero switch
+  // able to mute but never to unmute.
+  readonly property bool hasOutput: !!(volumeSink && volumeSink.audio)
+  readonly property bool hasInput: !!(source && source.audio)
+  readonly property bool anyAudible: (hasOutput && !outputMuted) || (hasInput && !inputMuted)
+  readonly property string toggleHint: anyAudible ? "Mute" : "Unmute"
 
   readonly property color hoverFill: bar
     ? Style.hoverFillFor(bar.foreground, Color.accent)
@@ -279,7 +285,7 @@ Panel {
 
   // Enter/Space: activate whatever the cursor is on.
   function activateCursor() {
-    if (focusSection === "header") { toggleOutputMute(); return }
+    if (focusSection === "header") { toggleAllMuted(); return }
     if (focusSection === "output") {
       if (selectedIndex === -1) { toggleOutputMute(); return }
       var sink = displayAudioSinks[selectedIndex]
@@ -432,6 +438,15 @@ Panel {
     if (source && source.audio) source.audio.muted = !source.audio.muted
   }
 
+  // The hero switch is the whole panel's on/off, so it carries both channels
+  // at once. It reads as on while anything is still audible, which keeps
+  // muting a single channel from the row below flipping the master switch.
+  function toggleAllMuted() {
+    var mute = anyAudible
+    if (hasOutput) volumeSink.audio.muted = mute
+    if (hasInput) source.audio.muted = mute
+  }
+
   function setDefaultSink(node) {
     if (!node) return
     Pipewire.preferredDefaultAudioSink = node
@@ -689,17 +704,17 @@ Panel {
             }
 
             // Compact on/off switch on the trailing edge of the hero, and the
-            // header's only cursor target. Checked means audible, so muting
-            // reads as switching the output off.
+            // header's only cursor target. Checked means something is still
+            // audible, so muting everything reads as switching audio off.
             ToggleSwitch {
               id: powerSwitch
-              checked: !root.outputMuted
+              checked: root.anyAudible
               hasCursor: root.headerHasCursor
               foreground: root.bar.foreground
               anchors.right: parent.right
               anchors.verticalCenter: parent.verticalCenter
               onHovered: function(on) { if (on) root.setHeaderCursor() }
-              onToggled: root.toggleOutputMute()
+              onToggled: root.toggleAllMuted()
 
               PanelToolTip {
                 visible: powerSwitch.containsMouse
@@ -803,6 +818,7 @@ Panel {
                 enabled: !!root.sink
 
                 onMoved: function(v) { root.setOutputVolume(v) }
+                onRightClicked: root.toggleOutputMute()
               }
 
               HoverHandler {
@@ -894,6 +910,7 @@ Panel {
                   enabled: !!root.source
 
                   onMoved: function(v) { root.setInputVolume(v) }
+                  onRightClicked: root.toggleInputMute()
                 }
 
                 Rectangle {
@@ -1181,6 +1198,10 @@ Panel {
         onMoved: function(v) {
           if (streamRow.node && streamRow.node.audio) streamRow.node.audio.volume = v
         }
+        onRightClicked: {
+          if (streamRow.node && streamRow.node.audio)
+            streamRow.node.audio.muted = !streamRow.node.audio.muted
+        }
       }
     }