feat(ui): single approve action merges the whole unit

Approve & Merge is now the only review+merge entry. For a parent with
children it drives the unit merge via the worker (conflicts still surface
through the existing PlanningMergeConflict dialog); the separate Merge All
Subtasks button, MergeAllCommand, CanMergeAll plumbing, and the dead
MergeAllPlanningAsync client method are removed. Combined-diff preview and
conflict continue/abort are kept.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs

@@ -59,7 +59,6 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task<MergeTargetsDto?> GetMergeTargetsAsync(string taskId);
     Task<IReadOnlyList<SubtaskDiffDto>> GetPlanningAggregateAsync(string planningTaskId);
     Task<CombinedDiffResultDto?> BuildPlanningIntegrationBranchAsync(string planningTaskId, string targetBranch);
-    Task MergeAllPlanningAsync(string planningTaskId, string targetBranch);
     Task ContinuePlanningMergeAsync(string planningTaskId);
     Task AbortPlanningMergeAsync(string planningTaskId);
     Task QueuePlanningSubtasksAsync(string parentTaskId, CancellationToken ct = default);

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -66,7 +66,7 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
 
     public event Action<PrimeFiredEvent>? PrimeFired;
 
-    public string? LastMergeAllTarget { get; private set; }
+    public string? LastApproveTarget { get; private set; }
 
     public WorkerClient(string signalRUrl)
     {
@@ -412,7 +412,10 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     }
 
     public Task<MergeResultDto?> ApproveReviewAsync(string taskId, string targetBranch)
-        => TryInvokeAsync<MergeResultDto>("ApproveReview", taskId, targetBranch);
+    {
+        LastApproveTarget = targetBranch;
+        return TryInvokeAsync<MergeResultDto>("ApproveReview", taskId, targetBranch);
+    }
 
     public Task<MergePreviewDto?> PreviewMergeAsync(string taskId, string targetBranch)
         => TryInvokeAsync<MergePreviewDto>("PreviewMerge", taskId, targetBranch);
@@ -486,12 +489,6 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public Task<CombinedDiffResultDto?> BuildPlanningIntegrationBranchAsync(string planningTaskId, string targetBranch)
         => TryInvokeAsync<CombinedDiffResultDto>("BuildPlanningIntegrationBranch", planningTaskId, targetBranch);
 
-    public async Task MergeAllPlanningAsync(string planningTaskId, string targetBranch)
-    {
-        LastMergeAllTarget = targetBranch;
-        await _hub.InvokeAsync("MergeAllPlanning", planningTaskId, targetBranch);
-    }
-
     public async Task ContinuePlanningMergeAsync(string planningTaskId)
     {
         await _hub.InvokeAsync("ContinuePlanningMerge", planningTaskId);

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

@@ -393,11 +393,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     // Planning merge controls
     [ObservableProperty] private ObservableCollection<string> _mergeTargetBranches = new();
     [ObservableProperty] private string? _selectedMergeTarget;
-    [ObservableProperty]
-    [NotifyCanExecuteChangedFor(nameof(MergeAllCommand))]
-    private bool _canMergeAll;
-    [ObservableProperty] private string? _mergeAllDisabledReason;
-    [ObservableProperty] private string? _mergeAllError;
 
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
@@ -580,13 +575,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
         Subtasks.CollectionChanged += (_, _) =>
         {
-            RecomputeCanMergeAll();
             ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
         };
 
         ChildOutcomes.CollectionChanged += (_, _) =>
         {
-            RecomputeCanMergeAll();
             ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
             NotifySessionSections();
         };
@@ -836,9 +829,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         OnPropertyChanged(nameof(HasChildOutcomes));
         MergeTargetBranches.Clear();
         SelectedMergeTarget = null;
-        CanMergeAll = false;
-        MergeAllDisabledReason = null;
-        MergeAllError = null;
         SessionOutcome = null;
         Roadblocks = null;
         _claudeBuf.Clear();
@@ -993,7 +983,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 }
             }
 
-            RecomputeCanMergeAll();
         }
         catch (OperationCanceledException) { }
         catch { /* best-effort */ }
@@ -1090,7 +1079,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 }
             }
 
-            RecomputeCanMergeAll();
         }
         catch (OperationCanceledException) { }
         catch { /* best-effort */ }
@@ -1115,7 +1103,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 existing.WorktreeState = child.Worktree?.State ?? ClaudeDo.Data.Models.WorktreeState.Active;
             }
 
-            RecomputeCanMergeAll();
         }
         catch { /* best-effort */ }
     }
@@ -1137,54 +1124,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             row.Status = child.Status;
             row.RoadblockCount = child.RoadblockCount;
             row.WorktreeState = child.Worktree?.State ?? ClaudeDo.Data.Models.WorktreeState.Active;
-            RecomputeCanMergeAll();
-            MergeAllCommand.NotifyCanExecuteChanged();
             ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
         }
         catch { /* best-effort */ }
     }
 
-    internal void RecomputeCanMergeAll()
-    {
-        // Improvement parent: merge is allowed once every child is terminal. The
-        // orchestrator folds the parent's own branch and skips failed/cancelled children.
-        if (ChildOutcomes.Count > 0)
-        {
-            var unfinished = ChildOutcomes.Count(c =>
-                c.Status != ClaudeDo.Data.Models.TaskStatus.Done
-                && c.Status != ClaudeDo.Data.Models.TaskStatus.Failed
-                && c.Status != ClaudeDo.Data.Models.TaskStatus.Cancelled);
-            if (unfinished > 0)
-            {
-                CanMergeAll = false;
-                MergeAllDisabledReason = $"{unfinished} improvement(s) not finished";
-                return;
-            }
-            CanMergeAll = true;
-            MergeAllDisabledReason = null;
-            return;
-        }
-
-        var notDone = Subtasks.Count(c => c.Status != ClaudeDo.Data.Models.TaskStatus.Done);
-        if (notDone > 0)
-        {
-            CanMergeAll = false;
-            MergeAllDisabledReason = $"{notDone} subtask(s) not done";
-            return;
-        }
-        var badWt = Subtasks.FirstOrDefault(c =>
-            c.WorktreeState == ClaudeDo.Data.Models.WorktreeState.Discarded ||
-            c.WorktreeState == ClaudeDo.Data.Models.WorktreeState.Kept);
-        if (badWt is not null)
-        {
-            CanMergeAll = false;
-            MergeAllDisabledReason = "at least one worktree was discarded/kept";
-            return;
-        }
-        CanMergeAll = true;
-        MergeAllDisabledReason = null;
-    }
-
     [RelayCommand(CanExecute = nameof(CanReviewDiff))]
     private async System.Threading.Tasks.Task ReviewCombinedDiffAsync()
     {
@@ -1196,20 +1140,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     private bool CanReviewDiff() => (Task?.IsPlanningParent == true && Subtasks.Any()) || HasChildOutcomes;
 
-    [RelayCommand(CanExecute = nameof(CanMergeAll))]
-    private async System.Threading.Tasks.Task MergeAllAsync()
-    {
-        MergeAllError = null;
-        try
-        {
-            await _worker.MergeAllPlanningAsync(Task!.Id, SelectedMergeTarget ?? "main");
-        }
-        catch (Exception ex)
-        {
-            MergeAllError = ex.Message;
-        }
-    }
-
     private async System.Threading.Tasks.Task RefreshWorktreeAsync(string taskId)
     {
         try
@@ -1526,8 +1456,9 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         if (Task is null || !_worker.IsConnected) return;
         try
         {
+            var hasChildren = Subtasks.Count > 0 || ChildOutcomes.Count > 0;
             var result = await _worker.ApproveReviewAsync(Task.Id, SelectedMergeTarget ?? "");
-            if (result?.Status == "conflict")
+            if (!hasChildren && result?.Status == "conflict")
             {
                 if (RequestConflictResolution is not null)
                 {
@@ -1540,6 +1471,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                     MergePreviewText = text; MergeIsClean = false; MergeIsConflict = true;
                 }
             }
+            // hasChildren: conflicts arrive via PlanningMergeConflictEvent → conflict dialog
         }
         catch { /* stale review action; broadcast reconciles */ }
     }

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -155,7 +155,7 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
 
         string subtaskTitle = subtaskId;
         string worktreePath = System.Environment.CurrentDirectory;
-        string targetBranch = Worker?.LastMergeAllTarget ?? "main";
+        string targetBranch = Worker?.LastApproveTarget ?? "main";
 
         try
         {

src/ClaudeDo.Ui/Views/Islands/Detail/WorkConsole.axaml

@@ -305,17 +305,7 @@
               </Button>
               <Button Classes="btn" Content="Review Combined Diff" Margin="0,0,8,8"
                       Command="{Binding ReviewCombinedDiffCommand}" />
-              <Button Classes="btn accent" Content="Merge All Subtasks" Margin="0,0,0,8"
-                      Command="{Binding MergeAllCommand}"
-                      IsEnabled="{Binding CanMergeAll}"
-                      ToolTip.Tip="{Binding MergeAllDisabledReason}" />
             </WrapPanel>
-
-            <TextBlock Text="{Binding MergeAllError}"
-                       Foreground="{DynamicResource BloodBrush}"
-                       TextWrapping="Wrap"
-                       IsVisible="{Binding MergeAllError,
-                           Converter={x:Static ObjectConverters.IsNotNull}}" />
           </StackPanel>
         </ScrollViewer>