audio: only show mic volume OSD through DMS IPCs, not external source

changes
fixes #2790
port 1.5

(cherry picked from commit 05feb211ba)

quickshell/Modules/OSD/MicVolumeOSD.qml

@@ -23,10 +23,10 @@ DankOSD {
     Connections {
         target: AudioService.source?.audio ?? null
 
+        // Sync only - apps adjusting mic gain (WebRTC AGC etc.) fire this
+        // constantly, so external volume changes must not surface the OSD
         function onVolumeChanged() {
             root._syncVolume();
-            if (SettingsData.osdMicVolumeEnabled)
-                root.show();
         }
 
         function onMutedChanged() {
@@ -38,6 +38,12 @@ DankOSD {
     Connections {
         target: AudioService
 
+        function onMicVolumeChanged() {
+            root._syncVolume();
+            if (SettingsData.osdMicVolumeEnabled)
+                root.show();
+        }
+
         function onSourceChanged() {
             root._syncVolume();
             if (root.shouldBeVisible && SettingsData.osdMicVolumeEnabled)