feat(ui): enable XC refresh only in Electron environment

Add an isElectron flag to PlaylistItemComponent and conditionally
render the refresh button only when running inside Electron.
This prevents exposing the server refresh action in non-Electron
(environments like the browser) where window.electron is unavailable
and the feature is not supported.

Update ensures safer behavior by checking !!window.electron in the
component and using that value in the template to guard the UI.

libs/ui/components/src/lib/recent-playlists/playlist-item/playlist-item.component.html

@@ -111,7 +111,7 @@
                     <mat-icon>sync</mat-icon>
                 </button>
             }
-            @if (item.serverUrl) {
+            @if (item.serverUrl && isElectron) {
                 <button
                     mat-icon-button
                     class="refresh-btn"

libs/ui/components/src/lib/recent-playlists/playlist-item/playlist-item.component.ts

@@ -33,6 +33,8 @@ export class PlaylistItemComponent implements OnInit {
     portalStatus: PortalStatus = 'unavailable';
     private readonly portalStatusService = inject(PortalStatusService);
 
+    readonly isElectron = !!window.electron;
+
     async ngOnInit() {
         await this.checkPortalStatus();
     }