fix(ui): Mission Control no longer lists finished operations as running

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs

@@ -158,22 +158,26 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         {
             var snapshot = await _worker.GetActiveOperationsAsync();
             RunningOperations.Clear();
-            foreach (var op in snapshot.OrderBy(o => o.StartedAt))
+            foreach (var op in snapshot.Where(o => !_endedOperationIds.Contains(o.Id)).OrderBy(o => o.StartedAt))
                 RunningOperations.Add(new RunningOperationViewModel(op));
             NotifyOperationsChanged();
         }
         catch (Exception ex) { ErrorReported?.Invoke(Loc.T("missionControl.operationsRefreshFailed", ex.Message)); }
     }
 
+    /// <summary>Ids already reported ended; guards against a late Started or a stale snapshot re-adding them. Op ids are unique, so it is never pruned (a few bytes per op).</summary>
+    private readonly HashSet<string> _endedOperationIds = new();
+
     private void AddOperation(RunningOperationDto op)
     {
-        if (RunningOperations.Any(r => r.Id == op.Id)) return;
+        if (_endedOperationIds.Contains(op.Id) || RunningOperations.Any(r => r.Id == op.Id)) return;
         RunningOperations.Add(new RunningOperationViewModel(op));
         NotifyOperationsChanged();
     }
 
     private void RemoveOperation(string id)
     {
+        _endedOperationIds.Add(id);
         var row = RunningOperations.FirstOrDefault(r => r.Id == id);
         if (row is null) return;
         RunningOperations.Remove(row);