fix(flutter): 统一详情页顶部圆形按钮

lib/pages/drama_detail/widgets/drama_detail_header.dart

@@ -18,8 +18,6 @@ const double _infoGap = 14;
 const double _favoriteHeight = 34;
 const double _favoriteRadius = 17;
 const double _favoriteHorizontal = 12;
-const double _circleSize = 36;
-const double _iconSize = 18;
 
 /// 详情页顶部操作与短剧主信息所需的交互回调。
 class DramaDetailHeaderActions {
@@ -87,10 +85,11 @@ class DramaDetailHeader extends StatelessWidget {
           onBack: actions.onBack,
         ),
         const Spacer(),
-        _CircleAction(
-          actionKey: const Key('detail-share'),
+        AppSubpageCircleButton(
+          buttonKey: const Key('detail-share'),
           tooltip: l10n.share,
           icon: Icons.share_outlined,
+          dark: true,
           onPressed: actions.onShare,
         ),
         const SizedBox(width: 8),
@@ -201,36 +200,3 @@ class DramaDetailHeader extends StatelessWidget {
     );
   }
 }
-
-class _CircleAction extends StatelessWidget {
-  const _CircleAction({
-    required this.actionKey,
-    required this.tooltip,
-    required this.icon,
-    required this.onPressed,
-  });
-
-  final Key actionKey;
-  final String tooltip;
-  final IconData icon;
-  final VoidCallback onPressed;
-
-  @override
-  Widget build(BuildContext context) {
-    return Container(
-      key: actionKey,
-      width: _circleSize,
-      height: _circleSize,
-      decoration: const BoxDecoration(
-        color: AppColors.card,
-        shape: BoxShape.circle,
-      ),
-      child: IconButton(
-        tooltip: tooltip,
-        onPressed: onPressed,
-        padding: EdgeInsets.zero,
-        icon: Icon(icon, size: _iconSize, color: AppColors.onSurface),
-      ),
-    );
-  }
-}