코워크와 코드 최종 응답 라이브 타이핑 프리뷰 적용

- Cowork/Code 에이전트 루프 완료 후 최종 답변이 한 번에 붙지 않도록 라이브 타이핑 프리뷰를 추가함\n- 처리 중에는 기존 진행 로그를 유지하고, 최종 응답 구간만 스트리밍 컨테이너를 거쳐 자연스럽게 이어지도록 정리함\n- README와 DEVELOPMENT 문서에 2026-04-07 02:31 (KST) 기준 변경 이력 반영\n- 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

@@ -5653,7 +5653,13 @@ public partial class ChatWindow : Window
             draftSucceeded = true;
 
             if (streamingContainer != null && streamingText != null)
+            {
                 FinalizeStreamingContainer(streamingContainer, streamingText, assistantContent);
+            }
+            else if (preparedExecution.Mode.UseAgentLoop && !string.IsNullOrWhiteSpace(assistantContent))
+            {
+                await ShowTypedAssistantPreviewAsync(assistantContent, _streamCts.Token);
+            }
         }
         catch (OperationCanceledException)
         {
@@ -5699,6 +5705,33 @@ public partial class ChatWindow : Window
         return new PreparedTurnOutcome(conversation, assistantContent, draftSucceeded, draftCancelled, draftFailure);
     }
 
+    private async Task ShowTypedAssistantPreviewAsync(string finalContent, CancellationToken ct)
+    {
+        if (string.IsNullOrWhiteSpace(finalContent) || MessagePanel == null)
+            return;
+
+        var container = CreateStreamingContainer(out var streamText);
+        _activeStreamText = streamText;
+        _cachedStreamContent = finalContent;
+        _displayedLength = 0;
+        _cursorVisible = true;
+        MessagePanel.Children.Add(container);
+        ForceScrollToEnd();
+        _cursorTimer.Start();
+        _typingTimer.Start();
+        streamText.Text = _cursorVisible ? "\u258c" : " ";
+
+        var deadline = DateTime.UtcNow.AddMilliseconds(Math.Clamp(finalContent.Length * 6, 500, 1800));
+        while (_displayedLength < _cachedStreamContent.Length && DateTime.UtcNow < deadline && !ct.IsCancellationRequested)
+            await Task.Delay(30, ct);
+
+        _displayedLength = _cachedStreamContent.Length;
+        if (_activeStreamText != null)
+            _activeStreamText.Text = _cachedStreamContent;
+
+        FinalizeStreamingContainer(container, streamText, finalContent);
+    }
+
     private void ScheduleExecutionHistoryRender(bool autoScroll = true)
     {
         _pendingExecutionHistoryAutoScroll |= autoScroll;