refactor(config): consolidate commit types into CommitTypeRegistry

Replaces six scattered "chore" literals across TaskEntity, ListEntity,
WorkerHub, ListsIslandViewModel, ListNavItemViewModel and the inline
commit type list in ListSettingsModalViewModel.

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

@@ -1,3 +1,4 @@
+using ClaudeDo.Data.Models;
 using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace ClaudeDo.Ui.ViewModels.Islands;
@@ -10,7 +11,7 @@ public sealed partial class ListNavItemViewModel : ViewModelBase
     [ObservableProperty] private int _count;
     [ObservableProperty] private bool _isActive;
     [ObservableProperty] private string? _workingDir;
-    [ObservableProperty] private string _defaultCommitType = "chore";
+    [ObservableProperty] private string _defaultCommitType = CommitTypeRegistry.DefaultType;
     public string? IconKey { get; init; }
     public string? DotColorKey { get; init; }
 }

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

@@ -163,7 +163,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase
         {
             Id = Guid.NewGuid().ToString("N"),
             Name = "New list",
-            DefaultCommitType = "chore",
+            DefaultCommitType = CommitTypeRegistry.DefaultType,
             CreatedAt = DateTime.UtcNow,
         };