feat(ui): Review-Merge-Button — Claude nimmt Waiting-for-Review pro Liste ab

Neuer Button in der virtuellen Review-Liste: öffnet das Merge-Helper-Auswahlmodal
im Review-Modus (alle WaitingForReview-Tasks repo-verknüpfter Listen, gruppiert
unter Listen-Headern, alle vorgetickt) und startet pro gewählter Liste eine
ConPTY-Handler-Session direkt in der Merge-Phase — via bestehendem Handoff-Spec
(nextPhase "merge"), kein Triage/Wait davor. Handler-Host-Task wie beim vollen
"Let Claude handle it"-Lauf (HandlerBaseCommit, IsManual).

src/ClaudeDo.Ui/ViewModels/Islands/ListsIslandViewModel.cs

@@ -105,6 +105,25 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
             LetClaudeHandleRequested?.Invoke(new MergeHelperRequest(rawId, ids));
     }
 
+    /// <summary>Raised once per list after the review-scoped selection dialog is confirmed;
+    /// the shell opens one merge-phase ConPTY tile per request.</summary>
+    public event Action<MergeHelperRequest>? MergeReviewsRequested;
+
+    // Review-list variant of LetClaudeHandleListAsync: offers every WaitingForReview task across
+    // all repo-linked lists and starts one merge-phase handler session per list picked.
+    [RelayCommand]
+    private async Task MergeReviewsAsync()
+    {
+        if (Dialogs is null || _services is null) return;
+        var vm = _services.GetRequiredService<MergeHelperSelectionModalViewModel>();
+        vm.ConfigureForReview();
+        await vm.LoadAsync();
+        var ids = await Dialogs.ShowMergeHelperSelectionAsync(vm);
+        if (ids is not { Count: > 0 }) return;
+        foreach (var (listId, taskIds) in vm.GroupSelectionByList(ids))
+            MergeReviewsRequested?.Invoke(new MergeHelperRequest(listId, taskIds));
+    }
+
     [RelayCommand]
     private void OpenInExplorer(ListNavItemViewModel? row)
     {