AX Agent 상단 탭 잘림 및 메시지 transcript 정렬 보정

- 상단 헤더 첫 행 높이와 중앙 탭 래퍼 패딩/최소 높이를 늘려 채팅, Cowork, 코드 탭 글자 잘림 수정
- 사용자, assistant, streaming 메시지 컨테이너를 동일 transcript 폭 기준으로 통일
- wrapper는 같은 중심 축을 공유하고 내부 bubble만 좌우 정렬되도록 변경해 메시지 박스 정렬 불일치 완화
- README 및 DEVELOPMENT 문서에 2026-04-05 23:22 (KST) 기준 변경 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 확인

src/AxCopilot/Views/ChatWindow.xaml

@@ -856,7 +856,7 @@
             <!-- ══════════════════════════════════════════════════════ -->
             <Grid Grid.Column="2">
                 <Grid.RowDefinitions>
-                    <RowDefinition Height="42"/>
+                    <RowDefinition Height="48"/>
                     <RowDefinition Height="Auto"/>  <!-- 서브 바: 제목 + 프리뷰 -->
                     <RowDefinition Height="Auto"/>  <!-- 스티키 진행률 바 -->
                     <RowDefinition Height="*"/>
@@ -1147,8 +1147,8 @@
                                 Background="{DynamicResource ItemBackground}"
                                 BorderBrush="{DynamicResource BorderColor}"
                                 BorderThickness="1"
-                                CornerRadius="16" Padding="4"
-                                MinHeight="40"
+                                CornerRadius="16" Padding="5"
+                                MinHeight="42"
                                 WindowChrome.IsHitTestVisibleInChrome="True">
                             <StackPanel Orientation="Horizontal">
                                 <RadioButton x:Name="TabChat" Content="채팅" Style="{StaticResource TopTabBtn}"

src/AxCopilot/Views/ChatWindow.xaml.cs

@@ -4425,11 +4425,13 @@ public partial class ChatWindow : Window
         if (isUser)
         {
             // 사용자: claw-code 쪽처럼 더 얇은 transcript 버블
+            var msgMaxWidth = GetMessageMaxWidth();
             var wrapper = new StackPanel
             {
-                HorizontalAlignment = HorizontalAlignment.Right,
-                MaxWidth = GetMessageMaxWidth(),
-                Margin = new Thickness(132, 4, 4, 6),
+                HorizontalAlignment = HorizontalAlignment.Center,
+                Width = msgMaxWidth,
+                MaxWidth = msgMaxWidth,
+                Margin = new Thickness(0, 4, 0, 6),
             };
 
             var bubble = new Border
@@ -4439,6 +4441,7 @@ public partial class ChatWindow : Window
                 BorderThickness = new Thickness(1),
                 CornerRadius = new CornerRadius(9),
                 Padding = new Thickness(11, 7, 11, 7),
+                HorizontalAlignment = HorizontalAlignment.Right,
                 Child = new TextBlock
                 {
                     Text = content,
@@ -4508,11 +4511,13 @@ public partial class ChatWindow : Window
             }
 
             // 어시스턴트: 카드보다 transcript 행에 가까운 스타일
+            var msgMaxWidth = GetMessageMaxWidth();
             var container = new StackPanel
             {
-                HorizontalAlignment = HorizontalAlignment.Left,
-                MaxWidth = GetMessageMaxWidth(),
-                Margin = new Thickness(4, 6, 132, 6)
+                HorizontalAlignment = HorizontalAlignment.Center,
+                Width = msgMaxWidth,
+                MaxWidth = msgMaxWidth,
+                Margin = new Thickness(0, 6, 0, 6)
             };
             if (animate) ApplyMessageEntryAnimation(container);
 
@@ -11378,10 +11383,10 @@ public partial class ChatWindow : Window
         var msgMaxWidth = GetMessageMaxWidth();
         var container = new StackPanel
         {
-            HorizontalAlignment = HorizontalAlignment.Left,
+            HorizontalAlignment = HorizontalAlignment.Center,
             Width = msgMaxWidth,
             MaxWidth = msgMaxWidth,
-            Margin = new Thickness(10, 3, 150, 3),
+            Margin = new Thickness(0, 3, 0, 3),
             Opacity = 0,
             RenderTransform = new TranslateTransform(0, 10)
         };