refactor(ui): test planning detail pane via real ViewModel and restore merge-all IsEnabled binding

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/AssemblyInfo.cs

@@ -0,0 +1,2 @@
+using System.Runtime.CompilerServices;
+[assembly: InternalsVisibleTo("ClaudeDo.Ui.Tests")]

src/ClaudeDo.Ui/Services/IWorkerClient.cs

@@ -1,7 +1,14 @@
+using System.ComponentModel;
+using ClaudeDo.Data.Models;
+
 namespace ClaudeDo.Ui.Services;
 
-public interface IWorkerClient
+public interface IWorkerClient : INotifyPropertyChanged
 {
+    bool IsConnected { get; }
+
+    event Action<string, string, DateTime>? TaskStartedEvent;
+    event Action<string, string, string, DateTime>? TaskFinishedEvent;
     event Action<string>? TaskUpdatedEvent;
     event Action<string>? WorktreeUpdatedEvent;
     event Action<string, string>? TaskMessageEvent;
@@ -13,6 +20,13 @@ public interface IWorkerClient
     event Action<string>? PlanningCompletedEvent;
 
     Task WakeQueueAsync();
+    Task RunNowAsync(string taskId);
+    Task ContinueTaskAsync(string taskId, string followUpPrompt);
+    Task ResetTaskAsync(string taskId);
+    Task CancelTaskAsync(string taskId);
+    Task<List<AgentInfo>> GetAgentsAsync();
+    Task<ListConfigDto?> GetListConfigAsync(string listId);
+    Task UpdateTaskAgentSettingsAsync(UpdateTaskAgentSettingsDto dto);
     Task StartPlanningSessionAsync(string taskId, CancellationToken ct = default);
     Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default);
     Task DiscardPlanningSessionAsync(string taskId, CancellationToken ct = default);

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

@@ -16,7 +16,7 @@ namespace ClaudeDo.Ui.ViewModels.Islands;
 public sealed partial class DetailsIslandViewModel : ViewModelBase
 {
     private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
-    private readonly WorkerClient _worker;
+    private readonly IWorkerClient _worker;
     private readonly IServiceProvider _services;
 
     // Current task row (set by IslandsShellViewModel via Bind)
@@ -151,7 +151,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     // Set by the view so DeleteTaskCommand can show an error message
     public Func<string, System.Threading.Tasks.Task>? ShowErrorAsync { get; set; }
 
-    public DetailsIslandViewModel(IDbContextFactory<ClaudeDoDbContext> dbFactory, WorkerClient worker, IServiceProvider services)
+    public DetailsIslandViewModel(IDbContextFactory<ClaudeDoDbContext> dbFactory, IWorkerClient worker, IServiceProvider services)
     {
         _dbFactory = dbFactory;
         _worker = worker;
@@ -545,7 +545,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         catch { /* best-effort */ }
     }
 
-    private void RecomputeCanMergeAll()
+    internal void RecomputeCanMergeAll()
     {
         var notDone = Subtasks.Count(c => c.Status != ClaudeDo.Data.Models.TaskStatus.Done);
         if (notDone > 0)

src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml

@@ -157,6 +157,7 @@
               <Button Content="Review combined diff"
                       Command="{Binding ReviewCombinedDiffCommand}"/>
               <Button Content="Merge all subtasks"
+                      IsEnabled="{Binding CanMergeAll}"
                       Command="{Binding MergeAllCommand}"
                       ToolTip.Tip="{Binding MergeAllDisabledReason}"/>
             </StackPanel>