refactor(shared): 공통 위젯 및 색상 정리

lib/src/shared/widgets/retro_panel.dart

@@ -37,8 +37,14 @@ class RetroPanel extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final painter = useGoldBorder
-        ? GoldBorderPainter(borderWidth: borderWidth, fillColor: backgroundColor)
-        : PixelBorderPainter(borderWidth: borderWidth, fillColor: backgroundColor);
+        ? GoldBorderPainter(
+            borderWidth: borderWidth,
+            fillColor: backgroundColor,
+          )
+        : PixelBorderPainter(
+            borderWidth: borderWidth,
+            fillColor: backgroundColor,
+          );
 
     return CustomPaint(
       painter: painter,
@@ -77,7 +83,9 @@ class _PanelTitle extends StatelessWidget {
             : RetroColors.panelBorderOuter.withValues(alpha: 0.5),
         border: Border(
           bottom: BorderSide(
-            color: useGoldBorder ? RetroColors.gold : RetroColors.panelBorderInner,
+            color: useGoldBorder
+                ? RetroColors.gold
+                : RetroColors.panelBorderInner,
             width: 1,
           ),
         ),