AX Agent 재생성 흐름과 엔진 마감 문구를 상태 기반으로 정리

- regenerate/retry가 MessagePanel 직접 삭제 대신 conversation state 수정 후 RenderMessages 경로를 타도록 정리

- AxAgentExecutionEngine에 UI용 마감 helper를 추가해 취소/오류/빈 응답과 Cowork·Code 완료 문구를 정상 한국어 기준으로 정규화

- Paused/Resumed 실행 이벤트는 debug가 아닐 때 기본 타임라인에서 숨겨 Cowork/Code 노이즈를 축소

- README와 docs/DEVELOPMENT.md에 2026-04-05 18:20 (KST) 기준 작업 이력 반영

- 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/Services/Agent/AxAgentExecutionEngine.cs

@@ -155,7 +155,7 @@ public sealed class AxAgentExecutionEngine
         string? content,
         ChatStorageService? storage = null)
     {
-        var normalized = NormalizeAssistantContent(conversation, tab, content);
+        var normalized = NormalizeAssistantContentForUi(conversation, tab, content);
         if (tab is "Cowork" or "Code")
             conversation.ShowExecutionHistory = false;
 
@@ -163,6 +163,47 @@ public sealed class AxAgentExecutionEngine
         return normalized;
     }
 
+    public FinalizedContent FinalizeExecutionContentForUi(string? currentContent, Exception? error = null, bool cancelled = false)
+    {
+        if (cancelled)
+        {
+            var content = string.IsNullOrWhiteSpace(currentContent) ? "(취소됨)" : currentContent!;
+            return new FinalizedContent(content, true, "사용자가 작업을 중단했습니다.");
+        }
+
+        if (error != null)
+            return new FinalizedContent($"오류: {error.Message}", false, error.Message);
+
+        return new FinalizedContent(currentContent ?? string.Empty, false, null);
+    }
+
+    public string NormalizeAssistantContentForUi(
+        ChatConversation conversation,
+        string runTab,
+        string? content)
+    {
+        if (!string.IsNullOrWhiteSpace(content))
+            return content;
+
+        var latestEventSummary = conversation.ExecutionEvents?
+            .Where(evt => !string.IsNullOrWhiteSpace(evt.Summary))
+            .OrderByDescending(evt => evt.Timestamp)
+            .Select(evt => evt.Summary.Trim())
+            .FirstOrDefault();
+
+        if (!string.IsNullOrWhiteSpace(latestEventSummary))
+        {
+            return runTab switch
+            {
+                "Cowork" => $"코워크 작업이 완료되었습니다.\n\n{latestEventSummary}",
+                "Code" => $"코드 작업이 완료되었습니다.\n\n{latestEventSummary}",
+                _ => latestEventSummary,
+            };
+        }
+
+        return "(빈 응답)";
+    }
+
     public FinalizedContent FinalizeExecutionContent(string? currentContent, Exception? error = null, bool cancelled = false)
     {
         if (cancelled)

src/AxCopilot/Views/ChatWindow.xaml.cs

@@ -8581,14 +8581,14 @@ public partial class ChatWindow : Window
         }
         catch (OperationCanceledException)
         {
-            var finalized = _chatEngine.FinalizeExecutionContent(assistantContent, cancelled: true);
+            var finalized = _chatEngine.FinalizeExecutionContentForUi(assistantContent, cancelled: true);
             assistantContent = finalized.Content;
             draftCancelled = finalized.Cancelled;
             draftFailure = finalized.FailureReason;
         }
         catch (Exception ex)
         {
-            var finalized = _chatEngine.FinalizeExecutionContent(assistantContent, ex);
+            var finalized = _chatEngine.FinalizeExecutionContentForUi(assistantContent, ex);
             assistantContent = finalized.Content;
             draftFailure = finalized.FailureReason;
             ShowToast("실패한 요청은 작업 요약에서 다시 시도할 수 있습니다.", "\uE783", 2600);
@@ -10393,6 +10393,10 @@ public partial class ChatWindow : Window
             return;
         }
 
+        if (!string.Equals(logLevel, "debug", StringComparison.OrdinalIgnoreCase)
+            && evt.Type is AgentEventType.Paused or AgentEventType.Resumed)
+            return;
+
         // simple 모드: ToolCall은 건너뜀 (ToolResult만 한 줄로 표시)
         if (logLevel == "simple" && evt.Type == AgentEventType.ToolCall)
             return;
@@ -10799,9 +10803,8 @@ public partial class ChatWindow : Window
             }
         }
 
-        // UI에서 마지막 AI 응답 제거
-        if (MessagePanel.Children.Count > 0)
-            MessagePanel.Children.RemoveAt(MessagePanel.Children.Count - 1);
+        RenderMessages(preserveViewport: true);
+        AutoScrollIfNeeded();
 
         // 재전송
         await SendRegenerateAsync(conv);
@@ -10913,14 +10916,19 @@ public partial class ChatWindow : Window
         // 마지막 assistant 메시지 제거
         lock (_convLock)
         {
-            if (conv.Messages.Count > 0 && conv.Messages[^1].Role == "assistant")
+            var session = ChatSession;
+            if (session != null)
+            {
+                session.RemoveLastAssistantMessage(_activeTab, _storage);
+                _currentConversation = session.CurrentConversation;
+                conv = _currentConversation!;
+            }
+            else if (conv.Messages.Count > 0 && conv.Messages[^1].Role == "assistant")
+            {
                 conv.Messages.RemoveAt(conv.Messages.Count - 1);
+            }
         }
 
-        // UI에서 마지막 AI 응답 제거
-        if (MessagePanel.Children.Count > 0)
-            MessagePanel.Children.RemoveAt(MessagePanel.Children.Count - 1);
-
         // 피드백을 사용자 메시지로 추가
         var feedbackMsg = new ChatMessage
         {