fix(app): decouple completion chime

Play the completion sound through the app with Web Audio so it is not tied to whether desktop notifications are enabled or whether a platform-specific notification sound name is supported.

Keep the notification body focused on completion status and leave the settings toggle available even when notifications are disabled.

src/App.tsx

@@ -42,9 +42,34 @@ const getScheduledQueueIds = () => {
   return selectedQueueIds;
 };
 
+type AudioContextConstructor = typeof AudioContext;
+
+const playCompletionChime = () => {
+  const AudioCtor =
+    window.AudioContext ||
+    (window as Window & { webkitAudioContext?: AudioContextConstructor }).webkitAudioContext;
+  if (!AudioCtor) return;
+
+  const context = new AudioCtor();
+  const oscillator = context.createOscillator();
+  const gain = context.createGain();
+  oscillator.type = 'sine';
+  oscillator.frequency.setValueAtTime(880, context.currentTime);
+  oscillator.frequency.exponentialRampToValueAtTime(1320, context.currentTime + 0.12);
+  gain.gain.setValueAtTime(0.0001, context.currentTime);
+  gain.gain.exponentialRampToValueAtTime(0.18, context.currentTime + 0.02);
+  gain.gain.exponentialRampToValueAtTime(0.0001, context.currentTime + 0.24);
+  oscillator.connect(gain);
+  gain.connect(context.destination);
+  oscillator.start();
+  oscillator.stop(context.currentTime + 0.24);
+  oscillator.onended = () => {
+    void context.close();
+  };
+};
+
 function App() {
   const platform = usePlatformInfo();
-  const platformOsRef = useRef(platform.os);
   const [filter, setFilter] = useState<SidebarFilter>('all');
   const [coreReady, setCoreReady] = useState(false);
 
@@ -115,10 +140,6 @@ function App() {
 
   const { addToast } = useToast();
 
-  useEffect(() => {
-    platformOsRef.current = platform.os;
-  }, [platform.os]);
-
   useEffect(() => {
     let active = true;
     const initialize = async () => {
@@ -520,24 +541,22 @@ function App() {
     const unlistenTerminalState = listen('download-state', (event) => {
       if (event.payload.status !== 'completed' && event.payload.status !== 'failed') return;
       const settings = useSettingsStore.getState();
+      if (event.payload.status === 'completed' && settings.playCompletionSound) {
+        try {
+          playCompletionChime();
+        } catch (error) {
+          console.error('Completion sound failed:', error);
+        }
+      }
       if (!settings.showNotifications) return;
 
       const item = useDownloadStore.getState().downloads.find(d => d.id === event.payload.id);
       const fileName = item?.fileName || 'A file';
-      const platformOs = platformOsRef.current;
-      const sound = settings.playCompletionSound
-        ? platformOs === 'macos'
-          ? 'Ping'
-          : platformOs === 'linux'
-            ? 'message-new-instant'
-            : undefined
-        : undefined;
       if (event.payload.status === 'completed') {
         try {
           sendNotification({
             title: 'Download Complete',
-            body: `${fileName} has finished downloading.`,
-            sound
+            body: `${fileName} has finished downloading.`
           });
         } catch (error) {
           console.error('Completion notification failed:', error);

src/components/SettingsView.tsx

@@ -526,19 +526,6 @@ runEngineChecks(false);
                     className="app-control w-24 text-center"
                   />
                 </div>
-                <div className="mac-settings-row">
-                  <div className="settings-row-label">
-                    <span>Global speed limit:</span>
-                    <small>{settings.globalSpeedLimit || 'Unlimited'}</small>
-                  </div>
-                  <button
-                    type="button"
-                    onClick={() => settings.setActiveView('speedLimiter')}
-                    className="app-button px-3 text-xs"
-                  >
-                    Configure…
-                  </button>
-                </div>
                 <div className="mac-settings-row">
                   <div className="settings-row-label">
                     <span>Automatic retries:</span>
@@ -571,12 +558,11 @@ runEngineChecks(false);
                     className="mac-switch"
                   />
                 </label>
-                <label className="mac-settings-row cursor-default" style={{ opacity: settings.showNotifications ? 1 : 0.5 }}>
+                <label className="mac-settings-row cursor-default">
                   <span className="text-[13px] text-text-primary">Play sound when download completes</span>
                   <input
                     type="checkbox"
                     checked={settings.playCompletionSound}
-                    disabled={!settings.showNotifications}
                     onChange={(e) => settings.setPlayCompletionSound(e.target.checked)}
                     className="mac-switch"
                   />