feat(ui): wire DetailsIsland ApproveMerge through MergeModal

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

@@ -106,6 +106,9 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     // Set by the view so OpenWorktreeCommand can show the modal as a dialog
     public Func<WorktreeModalViewModel, System.Threading.Tasks.Task>? ShowWorktreeModal { get; set; }
 
+    // Set by the view so ApproveMergeCommand can show the modal as a dialog
+    public Func<MergeModalViewModel, System.Threading.Tasks.Task>? ShowMergeModal { get; set; }
+
     // Set by the view so DeleteTaskCommand can prompt yes/no before deleting
     public Func<string, System.Threading.Tasks.Task<bool>>? ConfirmAsync { get; set; }
 
@@ -126,6 +129,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
                 RunNowCommand.NotifyCanExecuteChanged();
                 ContinueCommand.NotifyCanExecuteChanged();
                 ResetCommand.NotifyCanExecuteChanged();
+                ApproveMergeCommand.NotifyCanExecuteChanged();
             }
         };
 
@@ -304,6 +308,10 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         {
             WorktreePath = WorktreePath,
             BaseRef = WorktreeBaseCommit,
+            TaskId = Task?.Id,
+            TaskTitle = Task?.Title ?? "",
+            ShowMergeModal = ShowMergeModal,
+            ResolveMergeVm = () => _services.GetRequiredService<MergeModalViewModel>(),
         };
         await diffVm.LoadAsync();
         await ShowDiffModal(diffVm);
@@ -332,6 +340,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     {
         OpenDiffCommand.NotifyCanExecuteChanged();
         OpenWorktreeCommand.NotifyCanExecuteChanged();
+        ApproveMergeCommand.NotifyCanExecuteChanged();
     }
 
     [RelayCommand]
@@ -379,14 +388,18 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         await repo.UpdateAsync(entity);
     }
 
-    [RelayCommand]
+    [RelayCommand(CanExecute = nameof(CanMerge))]
     private async System.Threading.Tasks.Task ApproveMergeAsync()
     {
-        if (Task == null) return;
+        if (Task == null || ShowMergeModal == null) return;
-        // TODO: call worker merge hub method when available
+        var vm = _services.GetRequiredService<MergeModalViewModel>();
-        await System.Threading.Tasks.Task.CompletedTask;
+        await vm.InitializeAsync(Task.Id, Task.Title);
+        await ShowMergeModal(vm);
     }
 
+    private bool CanMerge() =>
+        Task != null && _worker.IsConnected && WorktreePath != null;
+
     [RelayCommand]
     private async System.Threading.Tasks.Task StopAsync()
     {