AX Agent 상태 스트립 갱신도 배치형으로 조정

- task summary 전용 타이머를 추가해 RuntimeActivityBadge와 ConversationStatusStrip 갱신을 120ms 단위로 묶음

- 실행 이벤트 본문 재렌더 배치와 함께 Cowork/Code 실행 중 UI 깜빡임을 줄이는 방향으로 정리함

- 검증: dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify\\ -p:IntermediateOutputPath=obj\\verify\\ 경고 0 / 오류 0

src/AxCopilot/Views/ChatWindow.xaml.cs

@@ -84,6 +84,7 @@ public partial class ChatWindow : Window
     private readonly DispatcherTimer _conversationSearchTimer;
     private readonly DispatcherTimer _inputUiRefreshTimer;
     private readonly DispatcherTimer _executionHistoryRenderTimer;
+    private readonly DispatcherTimer _taskSummaryRefreshTimer;
     private CancellationTokenSource? _gitStatusRefreshCts;
     private int _displayedLength; // 현재 화면에 표시된 글자 수
     private ResourceDictionary? _agentThemeDictionary;
@@ -244,6 +245,12 @@ public partial class ChatWindow : Window
                 AutoScrollIfNeeded();
             _pendingExecutionHistoryAutoScroll = false;
         };
+        _taskSummaryRefreshTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(120) };
+        _taskSummaryRefreshTimer.Tick += (_, _) =>
+        {
+            _taskSummaryRefreshTimer.Stop();
+            UpdateTaskSummaryIndicators();
+        };
 
         KeyDown += ChatWindow_KeyDown;
         UpdateConversationFailureFilterUi();
@@ -8549,6 +8556,7 @@ public partial class ChatWindow : Window
         _typingTimer.Stop();
         _executionHistoryRenderTimer.Stop();
         _pendingExecutionHistoryAutoScroll = false;
+        _taskSummaryRefreshTimer.Stop();
         HideStickyProgress();
         StopRainbowGlow();
         _activeStreamText = null;
@@ -8612,6 +8620,12 @@ public partial class ChatWindow : Window
         _executionHistoryRenderTimer.Start();
     }
 
+    private void ScheduleTaskSummaryRefresh()
+    {
+        _taskSummaryRefreshTimer.Stop();
+        _taskSummaryRefreshTimer.Start();
+    }
+
     // ─── 코워크 에이전트 지원 ────────────────────────────────────────────
 
     private string BuildCoworkSystemPrompt()
@@ -9070,7 +9084,7 @@ public partial class ChatWindow : Window
             }
         }
 
-        UpdateTaskSummaryIndicators();
+        ScheduleTaskSummaryRefresh();
     }
 
     private void OnSubAgentStatusChanged(SubAgentStatusEvent evt)
@@ -9078,7 +9092,7 @@ public partial class ChatWindow : Window
         Dispatcher.Invoke(() =>
         {
             _appState.ApplySubAgentStatus(evt);
-            UpdateTaskSummaryIndicators();
+            ScheduleTaskSummaryRefresh();
         });
     }