AX Agent 코드 메시지 강조와 Git 요약 배너 개선

- Cowork/Code 메시지 마크다운 렌더에 camelCase, PascalCase, snake_case 등 코드 심볼 강조를 추가함

- 코드 탭 입력부 위에 저장소/브랜치/변경 수치 요약 배너를 추가해 claude-code 스타일의 repo context를 빠르게 확인할 수 있게 함

- README와 DEVELOPMENT 문서를 2026-04-06 20:18 (KST) 기준으로 갱신함

- 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.MessageBubblePresentation.cs

@@ -51,10 +51,12 @@ public partial class ChatWindow
                 var userCodeBgBrush = TryFindResource("HintBackground") as Brush ?? Brushes.DarkGray;
                 MarkdownRenderer.EnableFilePathHighlight =
                     (System.Windows.Application.Current as App)?.SettingsService?.Settings.Llm.EnableFilePathHighlight ?? true;
+                MarkdownRenderer.EnableCodeSymbolHighlight = true;
                 bubble.Child = MarkdownRenderer.Render(content, primaryText, secondaryText, accentBrush, userCodeBgBrush);
             }
             else
             {
+                MarkdownRenderer.EnableCodeSymbolHighlight = false;
                 bubble.Child = new TextBlock
                 {
                     Text = content,
@@ -176,6 +178,9 @@ public partial class ChatWindow
         var app = System.Windows.Application.Current as App;
         MarkdownRenderer.EnableFilePathHighlight =
             app?.SettingsService?.Settings.Llm.EnableFilePathHighlight ?? true;
+        MarkdownRenderer.EnableCodeSymbolHighlight =
+            string.Equals(_activeTab, "Cowork", StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(_activeTab, "Code", StringComparison.OrdinalIgnoreCase);
         var codeBgBrush = TryFindResource("HintBackground") as Brush ?? Brushes.DarkGray;
         if (IsBranchContextMessage(content))
         {