fix: prevent error and aborted XHR on export notification click

The export notification href was a full external URL, causing the browser
to navigate away on click. This aborted the concurrent mark-as-read XHR
(status 0 / NS_BINDING_ABORTED), surfacing a spurious error dialog.

Override href() to return '#' to prevent page navigation, and override
markAsRead() to open the download via window.open(_blank) instead.
The mark-as-read XHR then completes cleanly without being aborted.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: imorland

js/src/forum/components/ExportAvailableNotification.ts

@@ -8,13 +8,17 @@ export default class ExportAvailableNotification extends Notification {
     return 'fas fa-file-export';
   }
 
-  href() {
+  exportUrl() {
     const exportModel = this.attrs.notification.subject() as Export;
-
-    // Building the full url scheme so that Mithril treats this as an external link, so the download will work correctly.
     return app.forum.attribute<string>('baseUrl') + `/gdpr/export/${exportModel.file()}`;
   }
 
+  href() {
+    // Return a non-navigating href; the download is opened via window.open() in
+    // markAsRead() so the mark-as-read XHR is not aborted by a page navigation.
+    return '#';
+  }
+
   content() {
     const notification = this.attrs.notification;
     return app.translator.trans('flarum-gdpr.forum.notification.export-ready', {
@@ -25,4 +29,16 @@ export default class ExportAvailableNotification extends Notification {
   excerpt() {
     return null;
   }
+
+  markAsRead() {
+    // Open the download in a new tab so the current page is not navigated away
+    // from, keeping the mark-as-read XHR alive.
+    window.open(this.exportUrl(), '_blank');
+
+    if (this.attrs.notification.isRead()) return;
+
+    app.session.user?.pushAttributes({ unreadNotificationCount: (app.session.user.unreadNotificationCount() ?? 1) - 1 });
+
+    this.attrs.notification.save({ isRead: true });
+  }
 }