feat(ui): ListsIslandViewModel with smart/virtual/user lists

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

src/ClaudeDo.Ui/ViewModels/Islands/ListNavItemViewModel.cs

@@ -6,6 +6,7 @@ public sealed partial class ListNavItemViewModel : ViewModelBase
 {
     public required string Id { get; init; }
     public required string Name { get; init; }
+    public required ListKind Kind { get; init; }
     [ObservableProperty] private int _count;
     [ObservableProperty] private bool _isActive;
     public string? IconKey { get; init; }