fix(ui): stop app crash when approving review after Merge all

The Details island review commands (Approve/Reject/Park/Cancel) invoked the
hub without catching exceptions. After "Merge all" folds the parent out of
WaitingForReview, pressing Approve made the hub throw a HubException, which
escaped the generated AsyncRelayCommand as an unobserved async-void exception
and crashed the app. Wrap the calls in try/catch like the Tasks island does;
the TaskUpdated broadcast reconciles the UI.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandPlanningTests.cs

@@ -63,12 +63,21 @@ public class DetailsIslandPlanningTests : IDisposable
         public Task DeleteAsync(string id) => Task.CompletedTask;
     }
 
-    private DetailsIslandViewModel BuildVm(FakeWorkerClient worker)
+    private DetailsIslandViewModel BuildVm(StubWorkerClient worker)
     {
         var factory = new TestDbFactory(NewContext);
         return new DetailsIslandViewModel(factory, worker, new NullServiceProvider(), new StubNotesApi());
     }
 
+    // Connected worker whose review calls fail the way the hub does when the task
+    // is no longer WaitingForReview (e.g. after "Merge all" folded the parent).
+    private sealed class ThrowingReviewWorkerClient : StubWorkerClient
+    {
+        public override bool IsConnected => true;
+        public override Task ApproveReviewAsync(string taskId) =>
+            Task.FromException(new InvalidOperationException("Task is not waiting for review; cannot approve."));
+    }
+
     private static SubtaskRowViewModel MakeSubtask(TaskStatus status, WorktreeState wt = WorktreeState.Active) =>
         new() { Id = Guid.NewGuid().ToString(), Title = "t", Status = status, WorktreeState = wt };
 
@@ -135,6 +144,21 @@ public class DetailsIslandPlanningTests : IDisposable
             vm.MergeAllDisabledReason.Contains("discarded", StringComparison.OrdinalIgnoreCase));
     }
 
+    // ── Review-action resilience: a failing hub call must not crash the app ───
+
+    [Fact]
+    public async Task ApproveReview_WhenWorkerThrows_DoesNotPropagate()
+    {
+        var vm = BuildVm(new ThrowingReviewWorkerClient());
+        vm.Bind(new TaskRowViewModel { Id = "p", Status = TaskStatus.WaitingForReview });
+
+        // Before the fix this surfaced the HubException as an unobserved
+        // async-void exception from the command, crashing the process.
+        var ex = await Record.ExceptionAsync(() => vm.ApproveReviewCommand.ExecuteAsync(null));
+
+        Assert.Null(ex);
+    }
+
     // ── Branch-load test exercising the VM via Bind ──────────────────────────
 
     [Fact]