fix: download button in desktop

auth/lib/services/update_service.dart

@@ -140,6 +140,7 @@ class LatestVersionInfo {
   final bool? shouldForceUpdate;
   final int lastSupportedVersionCode;
   final String? url;
+  final String? release;
   final int? size;
   final bool? shouldNotify;
 
@@ -150,6 +151,7 @@ class LatestVersionInfo {
     this.shouldForceUpdate,
     this.lastSupportedVersionCode,
     this.url,
+    this.release,
     this.size,
     this.shouldNotify,
   );
@@ -162,6 +164,7 @@ class LatestVersionInfo {
       map['shouldForceUpdate'],
       map['lastSupportedVersionCode'] ?? 1,
       map['url'],
+      map['release'],
       map['size'],
       map['shouldNotify'],
     );

auth/lib/ui/settings/app_update_dialog.dart

@@ -6,6 +6,7 @@ import 'package:ente_auth/ente_theme_data.dart';
 import 'package:ente_auth/l10n/l10n.dart';
 import 'package:ente_auth/services/update_service.dart';
 import 'package:ente_auth/theme/ente_theme.dart';
+import 'package:ente_auth/utils/platform_util.dart';
 import 'package:flutter/material.dart';
 import 'package:logging/logging.dart';
 import 'package:open_filex/open_filex.dart';
@@ -75,7 +76,9 @@ class _AppUpdateDialogState extends State<AppUpdateDialog> {
               ),
             ),
             onPressed: () => launchUrlString(
-              widget.latestVersionInfo!.url!,
+              PlatformUtil.isDesktop()
+                  ? widget.latestVersionInfo!.release!
+                  : widget.latestVersionInfo!.url!,
               mode: LaunchMode.externalApplication,
             ),
             child: Text(