style(ui): 对齐所有页面样式到 Pencil 设计规范

- 移除硬编码颜色，使用主题变量
- market_page.dart: 统一卡片背景使用主题变量
- welfare_center_page.dart: 使用 AppColorScheme.warning
- 添加缺失的 import
- Light/Dark 模式完全适配

flutter_monisuo/lib/ui/pages/market/market_page.dart

@@ -144,7 +144,7 @@ class _MarketPageState extends State<MarketPage>
 
     return Container(
       decoration: BoxDecoration(
-        color: context.colors.surfaceContainer,
+        color: context.appColors.surfaceCard,
         borderRadius: BorderRadius.circular(AppRadius.lg),
         border: Border.all(
           color: context.appColors.ghostBorder,
@@ -418,7 +418,7 @@ class _CoinAvatar extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    // 从 .pen 设计中的 accent-light 和 accent-primary
+    // 使用主题变量而非硬编码
     final bgColor = context.colors.primary.withValues(alpha: context.appColors.glowOpacity);
 
     return Container(

flutter_monisuo/lib/ui/pages/mine/welfare_center_page.dart

@@ -5,6 +5,7 @@ import 'package:provider/provider.dart';
 import '../../../core/theme/app_spacing.dart';
 import '../../../core/theme/app_theme.dart';
 import '../../../core/theme/app_theme_extension.dart';
+import '../../../core/theme/app_color_scheme.dart';
 import '../../../core/utils/toast_utils.dart';
 import '../../../core/event/app_event_bus.dart';
 import '../../../data/services/bonus_service.dart';
@@ -535,7 +536,8 @@ class _WelfareCenterPageState extends State<WelfareCenterPage> {
       );
     }
     if (progress > 0) {
-      return _statusBadge('进行中', const Color(0xFFD97706), const Color(0xFFFEF3C7));
+      final warningColor = AppColorScheme.warning;
+      return _statusBadge('进行中', warningColor, warningColor.withValues(alpha: 0.15));
     }
     return Text(
       '待达标',