Got adding working again

Bitvault/AggerateItemViewModelHandler.cs

@@ -0,0 +1,19 @@
+using Toolkit.Foundation;
+
+namespace Bitvault;
+
+public class AggerateItemViewModelHandler(IMediator mediator,
+    IServiceFactory serviceFactory,
+    IPublisher publisher) :
+    INotificationHandler<AggerateEventArgs<IItemEntryViewModel>>
+{
+    public Task Handle(AggerateEventArgs<IItemEntryViewModel> args)
+    {
+        if (serviceFactory.Create<ItemHeaderViewModel>(false) is ItemHeaderViewModel viewModel)
+        {
+            publisher.Publish(Create.As<IItemEntryViewModel>(viewModel), nameof(ItemViewModel));
+        }
+
+        return Task.CompletedTask;
+    }
+}