feat(app): 完善播放协议搜索与空状态

lib/core/theme/app_colors.dart

@@ -105,6 +105,7 @@ abstract final class AppColors {
   static const mineIconSupport = Color(0xFFA78BFA);
   static const mineIconLanguage = Color(0xFF22D3EE);
   static const mineIconSettings = Color(0xFFA1A1AA);
+  static const mineIconNotices = Color(0xFFFF8A4C);
   static const recommendPlaylistGlow = Color(0x26FF6B2C);
 
   /// 次级文字与列表 chevron。

lib/core/theme/app_dimens.dart

@@ -187,7 +187,7 @@ abstract final class AppDimens {
   static const double followingAddIconStroke = 1.5;
   static const double followingGridGap = 6;
   static const double followingGridRowGap = 12;
-  static const double followingCardTextExtent = 66;
+  static const double followingCardTextExtent = 70;
   static const double followingSubtitleFont = 12;
   static const double followingSubtitleGap = 4;
   static const double followingProgressHeight = 2;