fix(theater): 减小剧场搜索框圆角

lib/pages/discover/widgets/discover_search_field.dart

@@ -6,7 +6,7 @@ import '../../../core/theme/app_colors.dart';
 import '../../../l10n/app_localizations.dart';
 
 const double _searchHeight = 44;
-const double _searchRadius = 22;
+const double _searchRadius = 12;
 const double _searchPadding = 14;
 const double _iconSize = 18;
 const double _iconGap = 8;
@@ -16,7 +16,7 @@ const double _clearSize = 18;
 const double _clearIconSize = 12;
 const Duration _focusTransition = Duration(milliseconds: 160);
 
-/// 剧场顶部整行搜索框：浅灰胶囊，聚焦时变白并显示主题色描边。
+/// 剧场顶部整行搜索框：浅灰圆角，聚焦时变白并显示主题色描边。
 class DiscoverSearchField extends StatefulWidget {
   const DiscoverSearchField({
     super.key,