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.Data/Models/CommitTypeRegistry.cs

@@ -0,0 +1,11 @@
+namespace ClaudeDo.Data.Models;
+
+public static class CommitTypeRegistry
+{
+    public static readonly IReadOnlyList<string> Types = new[]
+    {
+        "chore", "feat", "fix", "refactor", "docs", "test", "ci", "perf", "style", "build",
+    };
+
+    public const string DefaultType = "chore";
+}

src/ClaudeDo.Data/Models/ListEntity.cs

@@ -6,7 +6,7 @@ public sealed class ListEntity
     public required string Name { get; set; }
     public required DateTime CreatedAt { get; init; }
     public string? WorkingDir { get; set; }
-    public string DefaultCommitType { get; set; } = "chore";
+    public string DefaultCommitType { get; set; } = CommitTypeRegistry.DefaultType;
 
     // Navigation properties
     public ListConfigEntity? Config { get; set; }

src/ClaudeDo.Data/Models/TaskEntity.cs

@@ -32,7 +32,7 @@ public sealed class TaskEntity
     public required DateTime CreatedAt { get; init; }
     public DateTime? StartedAt { get; set; }
     public DateTime? FinishedAt { get; set; }
-    public string CommitType { get; set; } = "chore";
+    public string CommitType { get; set; } = CommitTypeRegistry.DefaultType;
     public string? Model { get; set; }
     public string? SystemPrompt { get; set; }
     public string? AgentPath { get; set; }