style: 调整搜索结果两列布局

lib/core/theme/app_colors.dart

@@ -112,6 +112,7 @@ abstract final class AppColors {
   static const textTertiary = Color(0xFF8E8E93);
   static const textTabInactive = Color(0xFFB0B0B0);
   static const textFilterIcon = Color(0xFF7A7A7E);
+  static const searchResultMeta = Color(0xFF9E9E9E);
 
   /// 原生开屏与冷启动过渡底色。
   static const splashInk = ink;

lib/core/theme/app_dimens.dart

@@ -62,6 +62,12 @@ abstract final class AppDimens {
   static const double searchHeight = 40;
   static const double searchRadius = 8;
   static const double searchPlaceholderFont = 13;
+  static const double searchResultGap = 12;
+  static const double searchResultRowGap = 16;
+  static const double searchResultTitleGap = 8;
+  static const double searchResultMetaGap = 6;
+  static const double searchResultMetaFont = 12;
+  static const double searchResultTextExtent = 68;
   static const double navDot = 3;
   static const double glassBlur = 24;