diff --git a/src/ClaudeDo.Worker/Planning/PlanningAggregator.cs b/src/ClaudeDo.Worker/Planning/PlanningAggregator.cs
index 3938cdc..314b4e9 100644
--- a/src/ClaudeDo.Worker/Planning/PlanningAggregator.cs
+++ b/src/ClaudeDo.Worker/Planning/PlanningAggregator.cs
@@ -112,6 +112,23 @@ public sealed class PlanningAggregator
         return new CombinedDiffResult.Ok(new CombinedDiffSuccess(integrationBranch, unifiedDiff));
     }
 
+    public async Task CleanupIntegrationBranchAsync(string planningTaskId, CancellationToken ct)
+    {
+        var (planning, repoDir, _) = await LoadPlanningContextAsync(planningTaskId, ct);
+        var branch = BuildIntegrationBranchName(planning);
+
+        var current = await _git.GetCurrentBranchAsync(repoDir, ct);
+        if (string.Equals(current, branch, StringComparison.Ordinal))
+        {
+            var branches = await _git.ListLocalBranchesAsync(repoDir, ct);
+            var target = branches.FirstOrDefault(b => b != branch && !b.StartsWith("claudedo/", StringComparison.Ordinal)) ?? "main";
+            await _git.CheckoutBranchAsync(repoDir, target, ct);
+        }
+
+        try { await _git.BranchDeleteAsync(repoDir, branch, force: true, ct); }
+        catch { /* already gone — idempotent */ }
+    }
+
     private async Task<(TaskEntity planning, string repoDir, IReadOnlyList<TaskEntity> children)>
         LoadPlanningContextAsync(string planningTaskId, CancellationToken ct)
     {
diff --git a/tests/ClaudeDo.Worker.Tests/Planning/PlanningAggregatorTests.cs b/tests/ClaudeDo.Worker.Tests/Planning/PlanningAggregatorTests.cs
index d762f49..b125855 100644
--- a/tests/ClaudeDo.Worker.Tests/Planning/PlanningAggregatorTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/Planning/PlanningAggregatorTests.cs
@@ -194,6 +194,26 @@ public class PlanningAggregatorTests : IDisposable
         return (parentId, subA, subB);
     }
 
+    [Fact]
+    public async Task CleanupIntegrationBranchAsync_RemovesBranchIfPresent()
+    {
+        var db = NewDb();
+        var repo = NewRepo();
+        GitRepoFixture.RunGit(repo.RepoDir, "branch", "-m", "main");
+        var (parentId, _, _) = await SeedPlanningWithTwoChildrenAsync(db, repo);
+
+        var git = new GitService();
+        var svc = new PlanningAggregator(db.CreateFactory(), git, NullLogger<PlanningAggregator>.Instance);
+
+        var built = await svc.BuildIntegrationBranchAsync(parentId, "main", CancellationToken.None);
+        var ok = Assert.IsType<CombinedDiffResult.Ok>(built);
+
+        await svc.CleanupIntegrationBranchAsync(parentId, CancellationToken.None);
+
+        var branches = await git.ListLocalBranchesAsync(repo.RepoDir, CancellationToken.None);
+        Assert.DoesNotContain(branches, b => b == ok.Value.IntegrationBranch);
+    }
+
     private void SeedWorktreeWithFile(ClaudeDoDbContext ctx, GitRepoFixture repo, string taskId, string filename, string content)
     {
         var wtPath = Path.Combine(Path.GetTempPath(), $"wt_{Guid.NewGuid():N}");
diff --git a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
index 51d2bee..281c495 100644
--- a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
@@ -19,6 +19,10 @@ sealed class FakeWorkerClient : IWorkerClient
     public int FinalizePlanningCalls { get; private set; }
     public int WakeQueueCalls { get; private set; }
 
+    public bool IsConnected => false;
+    public event System.ComponentModel.PropertyChangedEventHandler? PropertyChanged;
+    public event Action<string, string, DateTime>? TaskStartedEvent;
+    public event Action<string, string, string, DateTime>? TaskFinishedEvent;
     public event Action<string>? TaskUpdatedEvent;
     public event Action<string>? WorktreeUpdatedEvent;
     public event Action<string, string>? TaskMessageEvent;
@@ -26,6 +30,13 @@ sealed class FakeWorkerClient : IWorkerClient
     public void RaiseWorktreeUpdated(string taskId) => WorktreeUpdatedEvent?.Invoke(taskId);
     public void RaiseTaskMessage(string taskId, string line) => TaskMessageEvent?.Invoke(taskId, line);
 
+    public Task RunNowAsync(string taskId) => Task.CompletedTask;
+    public Task ContinueTaskAsync(string taskId, string followUpPrompt) => Task.CompletedTask;
+    public Task ResetTaskAsync(string taskId) => Task.CompletedTask;
+    public Task CancelTaskAsync(string taskId) => Task.CompletedTask;
+    public Task<List<AgentInfo>> GetAgentsAsync() => Task.FromResult(new List<AgentInfo>());
+    public Task<ListConfigDto?> GetListConfigAsync(string listId) => Task.FromResult<ListConfigDto?>(null);
+    public Task UpdateTaskAgentSettingsAsync(UpdateTaskAgentSettingsDto dto) => Task.CompletedTask;
     public Task WakeQueueAsync() { WakeQueueCalls++; return Task.CompletedTask; }
     public Task StartPlanningSessionAsync(string taskId, CancellationToken ct = default) { StartPlanningCalls++; return Task.CompletedTask; }
     public Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default) { ResumePlanningCalls++; return Task.CompletedTask; }