fix(vip): render points exchange description

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/Content/VipServiceModal.php

@@ -239,11 +239,11 @@ trait VipServiceModal {
             return '';
         }
 
-        $desc_text = trim((string) ($points_ex['desc'] ?? ''));
+        $desc_text = trim((string) ($vip['points_exchange']['desc'] ?? ''));
         $desc = $desc_text !== ''
             // 管理员编辑的富文本说明：保存端已 wp_kses_post，这里同级别输出
             // （参考主题 zibpay_get_vip_points_exchange_modal 原样拼接）。
-            ? '<div class="muted-box muted-2-color padding-10 em09 mt20">' . wp_kses_post($desc_text) . '</div>'
+            ? '<div class="muted-box muted-2-color padding-10 em09 mt20 aksrt-vip-points-desc">' . wp_kses_post($desc_text) . '</div>'
             : '';
 
         // 最低价套餐仍超出用户积分 → 参考主题的 badg c-red btn-block 提示。