feat(miniprogram): 关怀模式全覆盖 — 58/58 页面 100% 接入

- 医生端 18 个页面全部接入（首页/待办/告警/咨询/透析/随访/
  患者/处方/报告及其详情和创建页）
- 商城子包 3 页面（商品详情/积分兑换/订单）
- 患者端剩余页面（AI报告/文章/活动/设备同步/登录/随访详情/
  报告详情/知情同意/诊断/透析处方/透析记录/家庭成员添加）
- 页面覆盖率：22/59 (37%) → 58/58 (100%)
- useElderClass hook 统一接入模式，零样板代码

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/miniprogram/src/pages/pkg-mall/exchange/index.tsx

@@ -8,6 +8,7 @@ import {
 import type { PointsProduct } from '../../../services/points';
 import { usePointsStore } from '../../../stores/points';
 import Loading from '../../../components/Loading';
+import { useElderClass } from '../../../hooks/useElderClass';
 import './index.scss';
 
 const TYPE_INITIAL: Record<string, string> = {
@@ -29,6 +30,7 @@ const TYPE_COLOR: Record<string, string> = {
 };
 
 export default function ExchangeConfirm() {
+  const modeClass = useElderClass();
   const [product, setProduct] = useState<PointsProduct | null>(null);
   const { account, refresh: refreshPoints } = usePointsStore();
   const [loading, setLoading] = useState(true);
@@ -119,7 +121,7 @@ export default function ExchangeConfirm() {
 
   if (loading) {
     return (
-      <View className='exchange-page'>
+      <View className={`exchange-page ${modeClass}`}>
         <Loading />
       </View>
     );
@@ -131,7 +133,7 @@ export default function ExchangeConfirm() {
   const typeColor = TYPE_COLOR[productType] || '#C4623A';
 
   return (
-    <View className='exchange-page'>
+    <View className={`exchange-page ${modeClass}`}>
       {/* 商品预览卡片 */}
       <View className='product-card'>
         <View