chore(claude-do): MCP: review_task/merge_task senden Progress während des Veri

## Symptom (real aufgetreten, 2026-08-11)

Ein `review_task(decision="approve")` über MCP lief >5 Min. Claude Codes MCP-Client brach den Call ab mit:

> MCP server "claudedo" tool "review_task" sent no response or progress for 300s; aborting.

Ergebnis: der Merge war **schon gelaufen und comitted** (`0e12be4`, `mergeCommit` am Worktree gesetzt), aber der Task blieb auf `WaitingForReview` hängen —

ClaudeDo-Task: d8199f1f-3df3-447f-8de2-e7aca9ec5064

tests/ClaudeDo.Worker.Tests/Services/TaskMergeServiceTests.cs

@@ -1675,13 +1675,19 @@ internal sealed class FakeVerifyCommandRunner : IVerifyCommandRunner
     public string? FileToCheck { get; set; }
     public bool? WorkingDirHadFile { get; private set; }
 
-    public Task<VerifyCommandResult> RunAsync(string workingDir, string command, TimeSpan timeout, CancellationToken ct)
+    // Simulates a slow build/test run so a progress-reporting test can observe at least one
+    // report without the real verify command ever taking that long.
+    public TimeSpan? Delay { get; set; }
+
+    public async Task<VerifyCommandResult> RunAsync(string workingDir, string command, TimeSpan timeout, CancellationToken ct)
     {
         CapturedWorkingDir = workingDir;
         CapturedCommand = command;
         if (FileToCheck is not null)
             WorkingDirHadFile = File.Exists(Path.Combine(workingDir, FileToCheck));
-        return Task.FromResult(Result);
+        if (Delay is { } delay)
+            await Task.Delay(delay, ct);
+        return Result;
     }
 }