feat: improve toast UI, add-modal cookie handling, and completion sounds

- Refine toast animations and durations
- Prevent extension-captured cookies from being sent across cross-origin redirects
- Clear stale extension metadata properly for single-link handoffs
- Disable completion sound by default and update settings labels
- Handle AudioContext suspension for completion chimes

src/store/useSettingsStore.ts

@@ -217,7 +217,7 @@ export const useSettingsStore = create<SettingsState>()(
       perServerConnections: 16,
       maxAutomaticRetries: 3,
       showNotifications: true,
-      playCompletionSound: true,
+      playCompletionSound: false,
       appFontSize: 'standard',
       listRowDensity: 'standard',
       showDockBadge: true,