AX Agent 토큰 사용 라벨 hover 종료와 스타일 정리

- 하단 컨텍스트 토큰 라벨이 hover 후 남아 있던 문제를 카드와 팝업의 실제 hover 상태 기준으로 닫히도록 수정
- 토큰 카드가 숨겨질 때 popup도 함께 닫히도록 보강
- 토큰 심볼과 popup 스타일을 얇은 테두리와 약한 그림자 중심으로 정리
- README와 DEVELOPMENT 문서에 2026-04-05 22:53 (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/Views/ChatWindow.xaml

@@ -1734,9 +1734,9 @@
                                             Width="28"
                                             Height="28"
                                             CornerRadius="999"
-                                            BorderBrush="Transparent"
-                                            BorderThickness="0"
-                                            Background="Transparent"
+                                            BorderBrush="{DynamicResource BorderColor}"
+                                            BorderThickness="1"
+                                            Background="{DynamicResource LauncherBackground}"
                                             VerticalAlignment="Center"
                                             Visibility="Collapsed"
                                             Cursor="Hand"
@@ -1744,8 +1744,8 @@
                                             MouseLeave="TokenUsageCard_MouseLeave">
                                         <Grid>
                                                 <Grid Width="28" Height="28" VerticalAlignment="Center">
-                                                <Ellipse Stroke="{DynamicResource HintBackground}"
-                                                         StrokeThickness="3"/>
+                                                <Ellipse Stroke="{DynamicResource BorderColor}"
+                                                         StrokeThickness="2.5"/>
                                                 <Path x:Name="TokenUsageArc"
                                                       Stroke="{DynamicResource AccentColor}"
                                                       StrokeThickness="3"
@@ -1812,13 +1812,13 @@
                                         <Border Background="{DynamicResource LauncherBackground}"
                                                 BorderBrush="{DynamicResource BorderColor}"
                                                 BorderThickness="1"
-                                                CornerRadius="14"
+                                                CornerRadius="12"
                                                 Padding="12,10"
                                                 MinWidth="186"
                                                 MouseEnter="TokenUsagePopup_MouseEnter"
                                                 MouseLeave="TokenUsagePopup_MouseLeave">
                                             <Border.Effect>
-                                                <DropShadowEffect BlurRadius="18" ShadowDepth="0" Opacity="0.16"/>
+                                                <DropShadowEffect BlurRadius="10" ShadowDepth="0" Opacity="0.08"/>
                                             </Border.Effect>
                                             <StackPanel>
                                                 <TextBlock x:Name="TokenUsagePopupTitle"

src/AxCopilot/Views/ChatWindow.xaml.cs

@@ -265,8 +265,7 @@ public partial class ChatWindow : Window
         _tokenUsagePopupCloseTimer.Tick += (_, _) =>
         {
             _tokenUsagePopupCloseTimer.Stop();
-            if (TokenUsagePopup != null)
-                TokenUsagePopup.IsOpen = false;
+            CloseTokenUsagePopupIfIdle();
         };
 
         KeyDown += ChatWindow_KeyDown;
@@ -18866,6 +18865,8 @@ private static (string icon, string label, string bgHex, string fgHex) GetDecisi
         TokenUsageCard.Visibility = showContextUsage ? Visibility.Visible : Visibility.Collapsed;
         if (!showContextUsage)
         {
+            if (TokenUsagePopup != null)
+                TokenUsagePopup.IsOpen = false;
             return;
         }
 
@@ -18989,6 +18990,17 @@ private static (string icon, string label, string bgHex, string fgHex) GetDecisi
         _tokenUsagePopupCloseTimer.Start();
     }
 
+    private void CloseTokenUsagePopupIfIdle()
+    {
+        if (TokenUsagePopup == null)
+            return;
+
+        var cardHovered = TokenUsageCard?.IsMouseOver ?? false;
+        var popupHovered = TokenUsagePopup.Child is FrameworkElement popupChild && popupChild.IsMouseOver;
+        if (!cardHovered && !popupHovered)
+            TokenUsagePopup.IsOpen = false;
+    }
+
     private static string BuildUsageModelKey(string? service, string? model)
     {
         var normalizedService = (service ?? "").Trim().ToLowerInvariant();