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/shell.qml

@@ -1104,11 +1104,20 @@ ShellRoot {
       active: slot.qmlCustom || slot.firstParty
       source: slot.qmlCustom ? root.customModuleSource(slot.moduleName) : (slot.firstParty ? slot.firstPartySource : "")
       anchors.fill: parent
-      onLoaded: {
-        if (item && "bar" in item) item.bar = root
-        if (item && "moduleName" in item) item.moduleName = slot.moduleName
-        if (item && "settings" in item) item.settings = root.moduleSettings(slot.moduleName)
-      }
+      onLoaded: slot.injectProps()
+    }
+
+    function injectProps() {
+      var target = qmlLoader.item
+      if (!target) return
+      if ("bar" in target) target.bar = root
+      if ("moduleName" in target) target.moduleName = moduleName
+      if ("settings" in target) target.settings = root.moduleSettings(moduleName)
+    }
+
+    Connections {
+      target: root
+      function onBarConfigSerialChanged() { slot.injectProps() }
     }
 
     Component {