refactor(claude-do): refactor(worker): move the merge and worktree MCP tools out

`src/ClaudeDo.Worker/External/ExternalMcpService.cs` ist **1897 Zeilen** (nachgezählt 2026-09-02; die Datei ist seit dem Anlegen dieses Tasks von 1696 weiter gewachsen): ~30 DTO-Records oben plus ~25 Tool-Methoden — während **13** Geschwisterdateien `*McpTools.cs` im selben Ordner das Topic-Split-Muster schon tragen (`ListMcpTools`, `ConfigMcpTools`, `BatchMcpTools`, `NotesMcpTools`, `QueueStateMc

ClaudeDo-Task: 1862e160-ffde-4a50-aa03-bb7251f56088

src/ClaudeDo.Worker/External/BatchMcpTools.cs

@@ -85,8 +85,13 @@ public sealed class BatchMcpTools
     };
 
     private readonly ExternalMcpService _svc;
+    private readonly WorktreeMcpTools _worktree;
 
-    public BatchMcpTools(ExternalMcpService svc) => _svc = svc;
+    public BatchMcpTools(ExternalMcpService svc, WorktreeMcpTools worktree)
+    {
+        _svc = svc;
+        _worktree = worktree;
+    }
 
     [McpServerTool, Description(
         "Fetch a snapshot of many tasks in one call — use for an overview or polling a fan-out instead of " +
@@ -365,7 +370,7 @@ public sealed class BatchMcpTools
             var id = taskIds[i];
             try
             {
-                var r = await _svc.CleanupTaskWorktree(id, force, cancellationToken);
+                var r = await _worktree.CleanupTaskWorktree(id, force, cancellationToken);
                 results.Add(new BatchCleanupResult(id, true, r.Removed, r.BranchDeleted, null, r.Number));
             }
             catch (OperationCanceledException) { throw; }

src/ClaudeDo.Worker/External/MergeMcpTools.cs

@@ -9,6 +9,7 @@ using ClaudeDo.Worker.Git;
 using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Lifecycle;
 using ClaudeDo.Worker.Planning;
+using Microsoft.EntityFrameworkCore;
 using ModelContextProtocol;
 using ModelContextProtocol.Server;
 using TaskStatus = ClaudeDo.Data.Models.TaskStatus;

src/ClaudeDo.Worker/External/WorktreeMcpTools.cs

@@ -1,10 +1,13 @@
 using System.ComponentModel;
 using System.Diagnostics;
 using ClaudeDo.Data;
+using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Git;
+using ClaudeDo.Worker.Lifecycle;
 using ClaudeDo.Worker.Worktrees;
+using Microsoft.EntityFrameworkCore;
 using ModelContextProtocol;
 using ModelContextProtocol.Server;
 using TaskStatus = ClaudeDo.Data.Models.TaskStatus;