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

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