fix(ui): 对齐所有页面样式到 Pencil 设计规范

transfer_page.dart:
- 金色主题统一（Light: secondary #F59E0B, Dark: primary #D4AF37）
- 修复交换按钮和确认按钮颜色

home_page.dart:
- Asset Card 圆角 14px
- 总资产字号 28px (displayLarge)
- "预估总资产"字号 13px (bodyLarge)
- 盈亏标签/数值字重调整

quick_actions_row.dart:
- padding 统一为 16px

welfare_center_page.dart:
- _statusBadge padding [6, 14]

trade_form_card.dart / price_card.dart:
- 样式细节对齐

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

@@ -93,7 +93,7 @@ class _WelfareCenterPageState extends State<WelfareCenterPage> {
   /// 状态胶囊标签
   Widget _statusBadge(String text, Color textColor, Color bgColor) {
     return Container(
-      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
+      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 6), // [4,10] → [6,14]
       decoration: BoxDecoration(
         color: bgColor,
         borderRadius: BorderRadius.circular(AppRadius.sm),
@@ -223,6 +223,7 @@ class _WelfareCenterPageState extends State<WelfareCenterPage> {
           Text(
             referralCode.isEmpty ? '暂无邀请码' : referralCode,
             style: AppTextStyles.displayMedium(context).copyWith(
+              fontSize: 24, // 明确设置为 24px
               fontWeight: FontWeight.w800,
               color: goldAccent,
               letterSpacing: 2,
@@ -444,7 +445,9 @@ class _WelfareCenterPageState extends State<WelfareCenterPage> {
                           const SizedBox(width: 10),
                           Text(
                             username,
-                            style: AppTextStyles.headlineSmall(context),
+                            style: AppTextStyles.headlineSmall(context).copyWith(
+                              fontWeight: FontWeight.w500, // 添加 w500
+                            ),
                           ),
                           const SizedBox(width: 10),
                           Text(