AX Agent 프리뷰 UI를 claw-code 스타일로 정리하고 프리뷰 surface를 공통화

- AX Agent 권한 승인 프리뷰에 공통 preview surface helper를 도입해 제목/요약/본문 box 구성을 일관되게 정리함
- 우측 파일 프리뷰 패널에 파일명, 경로, 형식·크기 메타 헤더를 추가하고 텍스트 프리뷰를 bordered preview box 안에 렌더하도록 개선함
- README와 DEVELOPMENT 문서에 2026-04-06 01:08 (KST) 기준 변경 이력 반영 완료
- dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify\\ -p:IntermediateOutputPath=obj\\verify\\ 경고 0 / 오류 0 확인

src/AxCopilot/Views/AgentPreviewSurfaceFactory.cs

@@ -0,0 +1,85 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+
+namespace AxCopilot.Views;
+
+internal static class AgentPreviewSurfaceFactory
+{
+    internal static Border CreateSurface(
+        string title,
+        string summary,
+        UIElement body,
+        Brush primary,
+        Brush secondary,
+        Brush itemBackground,
+        Brush borderBrush,
+        Thickness? margin = null)
+    {
+        return new Border
+        {
+            Background = itemBackground,
+            BorderBrush = borderBrush,
+            BorderThickness = new Thickness(1),
+            CornerRadius = new CornerRadius(12),
+            Padding = new Thickness(12, 10, 12, 10),
+            Margin = margin ?? new Thickness(0, 8, 0, 0),
+            Child = new StackPanel
+            {
+                Children =
+                {
+                    new TextBlock
+                    {
+                        Text = title,
+                        FontSize = 12,
+                        FontWeight = FontWeights.SemiBold,
+                        Foreground = primary,
+                    },
+                    new TextBlock
+                    {
+                        Text = summary,
+                        FontSize = 11,
+                        Foreground = secondary,
+                        Margin = new Thickness(0, 2, 0, 8),
+                        TextWrapping = TextWrapping.Wrap,
+                    },
+                    body
+                }
+            }
+        };
+    }
+
+    internal static Border CreatePreviewBox(
+        string content,
+        Brush primary,
+        Brush secondary,
+        Brush borderBrush,
+        double maxHeight,
+        bool monospace = true)
+    {
+        var panel = new Border
+        {
+            Background = Brushes.Transparent,
+            BorderBrush = new SolidColorBrush(Color.FromArgb(0x20, 0x80, 0x80, 0x80)),
+            BorderThickness = new Thickness(1),
+            CornerRadius = new CornerRadius(8),
+            Padding = new Thickness(8, 6, 8, 6),
+            Child = new ScrollViewer
+            {
+                MaxHeight = maxHeight,
+                VerticalScrollBarVisibility = ScrollBarVisibility.Auto,
+                Content = new TextBlock
+                {
+                    Text = string.IsNullOrWhiteSpace(content) ? "(empty)" : content,
+                    Foreground = primary,
+                    FontFamily = monospace ? new FontFamily("Consolas") : new FontFamily("Pretendard"),
+                    FontSize = 11.2,
+                    TextWrapping = TextWrapping.Wrap,
+                    LineHeight = 18,
+                }
+            }
+        };
+
+        return panel;
+    }
+}