chore(worker): register TaskMergeService

src/ClaudeDo.Worker/Program.cs

@@ -31,6 +31,7 @@ builder.Services.AddSingleton<ClaudeArgsBuilder>();
 builder.Services.AddSingleton<TaskRunner>();
 builder.Services.AddSingleton<WorktreeMaintenanceService>();
 builder.Services.AddSingleton<TaskResetService>();
+builder.Services.AddSingleton<TaskMergeService>();
 
 // Agent file management.
 var agentsDir = Path.Combine(ClaudeDo.Data.Paths.AppDataRoot(), "agents");