fix(ui): 拆分媒体骨架底色，恢复可见度

lib/core/theme/app_colors.dart

@@ -78,7 +78,12 @@ abstract final class AppColors {
   /// 中性深灰卡片与控件表面。
   static const contentCard = Color(0xFF16161A);
   static const contentSurface = Color(0xFF1C1C1E);
+
+  /// 首页、分类与搜索网格骨架的极暗底色。
   static const skeletonSurface = Color(0xFF0E0E0E);
+
+  /// 播放器、推荐与详情页大面积媒体占位的深灰底色。
+  static const skeletonMedia = Color(0xFF1C1C1E);
   static const contentChip = Color(0xFF2C2C2E);
   static const contentBorder = Color(0x1AFFFFFF);
   static const filterChipSelected = Color(0xFF21090E);

lib/pages/drama_detail/widgets/drama_episode_states.dart

@@ -13,7 +13,7 @@ const double _gridSpacing = 8;
 const double _radius = 10;
 const double _horizontal = 14;
 const double _sectionTop = 16;
-const double _minOpacity = 0.65;
+const double _minOpacity = 0.45;
 const double _maxOpacity = 0.8;
 const Duration _breathDuration = Duration(milliseconds: 900);
 
@@ -94,7 +94,7 @@ class _DramaEpisodesLoadingState extends State<DramaEpisodesLoading>
               opacity: _opacity,
               child: Container(
                 decoration: BoxDecoration(
-                  color: AppColors.skeletonSurface,
+                  color: AppColors.skeletonMedia,
                   borderRadius: BorderRadius.circular(_radius),
                 ),
               ),

lib/pages/recommend/recommend_page.dart

@@ -426,7 +426,7 @@ class _RecommendFeedSkeleton extends StatelessWidget {
               height: 176,
               child: DecoratedBox(
                 decoration: BoxDecoration(
-                  color: AppColors.skeletonSurface,
+                  color: AppColors.skeletonMedia,
                   borderRadius: BorderRadius.all(Radius.circular(12)),
                 ),
               ),
@@ -465,7 +465,7 @@ class _SkeletonLine extends StatelessWidget {
       width: width,
       height: height,
       decoration: BoxDecoration(
-        color: AppColors.skeletonSurface,
+        color: AppColors.skeletonMedia,
         borderRadius: BorderRadius.circular(6),
       ),
     );

test/theme/app_theme_test.dart

@@ -26,6 +26,8 @@ void main() {
     expect(AppColors.cardAlt, const Color(0xFF101010));
     expect(AppColors.raised, const Color(0xFF1C1C1E));
     expect(AppColors.border, const Color(0xFF1C1C1E));
+    expect(AppColors.skeletonSurface, const Color(0xFF0E0E0E));
+    expect(AppColors.skeletonMedia, const Color(0xFF1C1C1E));
     expect(AppColors.textPrimary, const Color(0xFFFFFFFF));
     expect(AppColors.textSecondary, const Color(0xFFB0B0B0));
     expect(AppColors.textTertiary, const Color(0xFF8E8E93));