feat(ui): open merge-helper ConPTY tile from selection

src/ClaudeDo.Localization/locales/de.json

@@ -268,6 +268,7 @@
     "overviewMode": "Übersicht",
     "closeSession": "Sitzung schließen",
     "conptyLaunchFailed": "ConPTY-Sitzung konnte nicht geöffnet werden: {0}",
+    "mergeHelperTitle": "Merge-Helfer",
     "submitForReviewFailed": "Einreichen zum Review fehlgeschlagen: {0}",
     "submitForReview": "Zum Review einreichen",
     "submitForReviewTip": "Diesen Worktree committen und den Task ins Review bringen, damit er gemergt werden kann",

src/ClaudeDo.Localization/locales/en.json

@@ -268,6 +268,7 @@
     "overviewMode": "Overview",
     "closeSession": "Close session",
     "conptyLaunchFailed": "Couldn't open ConPTY session: {0}",
+    "mergeHelperTitle": "Merge Helper",
     "submitForReviewFailed": "Couldn't submit for review: {0}",
     "submitForReview": "Submit for review",
     "submitForReviewTip": "Commit this worktree and move the task to review so it can be merged",

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -238,6 +238,11 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
             OpenMissionControl();
             _ = MissionControl.OpenPlanningConPtySessionAsync(taskId, resume);
         };
+        Lists.LetClaudeHandleRequested += req =>
+        {
+            OpenMissionControl();
+            _ = MissionControl.OpenMergeHelperConPtySessionAsync(req.ListId, req.TaskIds);
+        };
         Tasks.TasksChanged     += (_, _) => _ = Lists.RefreshCountsAsync();
         Tasks.OpenListSettingsRequested += (_, _) =>
         {

src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs

@@ -322,6 +322,40 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         }
     }
 
+    // Merge-helper session over a hand-picked set of tasks ("Let Claude handle it").
+    // Ad-hoc style: no owning task, never deduped — every run opens a fresh pane.
+    public async System.Threading.Tasks.Task OpenMergeHelperConPtySessionAsync(string? listId, IReadOnlyList<string> taskIds)
+    {
+        if (taskIds is not { Count: > 0 }) return;
+
+        var title = Loc.T("missionControl.mergeHelperTitle");
+        if (listId is not null)
+        {
+            try
+            {
+                await using var ctx = await _dbFactory.CreateDbContextAsync();
+                var list = await ctx.Lists.AsNoTracking().FirstOrDefaultAsync(l => l.Id == listId);
+                if (list?.Name is { Length: > 0 } name) title = $"{title} — {name}";
+            }
+            catch { /* best-effort title lookup */ }
+        }
+
+        try
+        {
+            var spec = await _worker.GetMergeHelperLaunchSpecAsync(taskIds, listId);
+            var descriptor = new TerminalLaunchDescriptor(spec.Cwd, spec.Exe, spec.Args, spec.Env);
+            var pane = ConPtyPaneViewModel.CreateAdHoc(title, descriptor);
+            pane.ErrorReported += OnConPtyPaneError;
+            pane.CloseRequested += CloseConPtySession;
+            pane.SubmitForReviewRequested += OnPaneSubmitForReview;
+            ConPtySessions.Add(pane);
+        }
+        catch (Exception ex)
+        {
+            ErrorReported?.Invoke(Loc.T("missionControl.conptyLaunchFailed", ex.Message));
+        }
+    }
+
     private void OnConPtyPaneError(string message) => ErrorReported?.Invoke(message);
 
     // Submit a task's hand-driven ConPTY work for review, then close the pane (the interactive

tests/ClaudeDo.Ui.Tests/ViewModels/MissionControlViewModelTests.cs

@@ -406,6 +406,65 @@ public class MissionControlViewModelTests : IDisposable
         Assert.Empty(vm.Panes);
     }
 
+    private sealed class ThrowingMergeHelperLaunchSpecWorker : StubWorkerClient
+    {
+        public override Task<LaunchSpec> GetMergeHelperLaunchSpecAsync(IReadOnlyList<string> taskIds, string? listId, CancellationToken ct = default)
+            => throw new InvalidOperationException("spec failed");
+    }
+
+    [Fact]
+    public async Task OpenMergeHelperConPtySessionAsync_AddsAdHocPane()
+    {
+        var worker = new FakeWorker();
+        using var vm = BuildVm(worker);
+
+        await vm.OpenMergeHelperConPtySessionAsync(null, new[] { "t1", "t2" });
+
+        Assert.Single(vm.ConPtySessions);
+        Assert.Null(vm.ConPtySessions[0].TaskId);
+        Assert.Single(vm.Panes);
+        Assert.Same(vm.ConPtySessions[0], vm.Panes[0]);
+    }
+
+    [Fact]
+    public async Task OpenMergeHelperConPtySessionAsync_TwoRuns_NeverDeduped()
+    {
+        var worker = new FakeWorker();
+        using var vm = BuildVm(worker);
+
+        await vm.OpenMergeHelperConPtySessionAsync(null, new[] { "t1" });
+        await vm.OpenMergeHelperConPtySessionAsync(null, new[] { "t1" });
+
+        Assert.Equal(2, vm.ConPtySessions.Count);
+    }
+
+    [Fact]
+    public async Task OpenMergeHelperConPtySessionAsync_EmptySelection_NoPane()
+    {
+        var worker = new FakeWorker();
+        using var vm = BuildVm(worker);
+
+        await vm.OpenMergeHelperConPtySessionAsync(null, Array.Empty<string>());
+
+        Assert.Empty(vm.ConPtySessions);
+        Assert.Empty(vm.Panes);
+    }
+
+    [Fact]
+    public async Task OpenMergeHelperConPtySessionAsync_WorkerThrows_RaisesErrorReported_NoPaneAdded()
+    {
+        var worker = new ThrowingMergeHelperLaunchSpecWorker();
+        using var vm = BuildVm(worker);
+        string? error = null;
+        vm.ErrorReported += msg => error = msg;
+
+        await vm.OpenMergeHelperConPtySessionAsync(null, new[] { "t1" });
+
+        Assert.Empty(vm.ConPtySessions);
+        Assert.Empty(vm.Panes);
+        Assert.NotNull(error);
+    }
+
     [Fact]
     public void ToggleLayoutCommand_FlipsIsFocusMode()
     {