Review everything shipped this weekend, and fix what the reviewers caught

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

config/dot/quickshell/services/SoundDefaults.qml

@@ -87,9 +87,19 @@ Singleton {
         return output ? root.absentSink : root.absentSource;
     }
 
+    // Assigning `running = true` to a Process that is already running is a
+    // no-op, not a queue. The default sink and source change together, so the
+    // two Pipewire signals below arrive back to back and the second read was
+    // always the one dropped -- which is how a ghost row survived the device
+    // coming back. Remembered here and re-run from reader.onExited instead.
+    property bool refreshPending: false
+
     function refresh(): void {
-        if (reader.running)
+        if (reader.running) {
+            root.refreshPending = true;
             return;
+        }
+        root.refreshPending = false;
         reader.command = root.fixturePath !== ""
             ? ["cat", root.fixturePath]
             : ["pw-metadata", "-n", "default", "0"];
@@ -173,6 +183,10 @@ Singleton {
                 : "PipeWire's remembered default devices could not be read.";
             if (code !== 0)
                 root.loaded = true;
+            // Deferred a turn so this read's stdout is parsed before the next
+            // one starts filling the same collector.
+            if (root.refreshPending)
+                Qt.callLater(() => root.refresh());
         }
     }