Address momus review: fix icons, vertical layout, popup coordination

- Replace nerd font glyphs that were stripped during the initial widget
  writes with verified codepoints sourced from the JetBrains Mono Nerd
  Font cmap (cpu-64-bit, scale-balance, notification-clear-all, etc).
- systemStats now switches to a Column layout when the bar is vertical
  so the widget no longer overflows a 28px-wide side bar.
- Remove notificationCenter from defaults: it registers a notification
  server and would collide with the mako daemon Omarchy autostarts.
- PopupCard owns the popout coordinator lifecycle and delegates close to
  its widget owner when provided; calendar and media now pass owner.
- brightness debounces brightnessctl writes through a coalescing timer
  to avoid spawning a process per slider tick.
- audioPanel tracks unfiltered Pipewire sinks/streams via PwObjectTracker
  so audio metadata becomes available before filtering.
- ModuleSlot re-injects bar/moduleName/settings whenever the bar config
  serial changes so widget settings update live with bar.json.
- Guard null bar references in workspacesPro and systemStats components
  that are constructed before bar injection.

default/quickshell/bar/widgets/brightness.qml

@@ -35,11 +35,29 @@ Item {
     if (!readProc.running) readProc.running = true
   }
 
+  property int pendingPercent: -1
+
   function setBrightness(percent) {
     var clamped = Math.max(1, Math.min(100, Math.round(percent)))
     currentPercent = clamped
-    writeProc.command = ["bash", "-lc", "brightnessctl set " + clamped + "% >/dev/null"]
-    writeProc.running = true
+    pendingPercent = clamped
+    writeTimer.restart()
+  }
+
+  Timer {
+    id: writeTimer
+    interval: 60
+    repeat: false
+    onTriggered: {
+      if (writeProc.running) {
+        writeTimer.restart()
+        return
+      }
+      if (pendingPercent < 0) return
+      writeProc.command = ["bash", "-lc", "brightnessctl set " + pendingPercent + "% >/dev/null"]
+      pendingPercent = -1
+      writeProc.running = true
+    }
   }
 
   Component.onCompleted: refresh()