blocked all nextcloud requests in demo mode to stop fake-credential logins tripping brute-force protection

lib/widget/downloads/download_trigger.dart

@@ -6,6 +6,7 @@ import '../../share_intent/remote_file_ref.dart';
 import '../../utils/downloads/download_job.dart';
 import '../../utils/downloads/download_manager.dart';
 import '../confirm_dialog.dart';
+import '../demo_restricted.dart';
 
 /// Shared download trigger logic for the Files list and Talk chat bubbles.
 ///
@@ -71,7 +72,7 @@ mixin DownloadTrigger<T extends StatefulWidget> on State<T> {
     RemoteFileRef? remoteFile,
   }) async {
     final path = downloadRemotePath;
-    if (path == null) return;
+    if (path == null || guardDemoAction(context)) return;
     final job = await DownloadManager.instance.start(
       remotePath: path,
       name: name,