refactor(mp): 迁移剩余 8 特殊页面到统一组件库

- 首页/健康/我的/商城/消息 TabBar 页面使用 PageShell 替代手写容器
- 登录/法律条款/关怀模式设置页使用 PageShell 替代手写容器
- 各页面卡片统一使用 ContentCard 组件
- 清理页面 SCSS 中的 min-height/background/padding 样板代码
- 66 个小程序页面全部完成统一组件迁移

apps/miniprogram/src/pages/pkg-profile/elder-mode/index.scss

@@ -2,17 +2,11 @@
 @import '../../../styles/mixins.scss';
 
 .elder-mode-page {
-  min-height: 100vh;
-  background: $bg;
-  padding: 24px;
+  // PageShell 接管 min-height, background, padding
 }
 
 .elder-mode-card {
-  background: $card;
-  border-radius: $r;
-  padding: 24px;
-  box-shadow: $shadow-md;
-  margin-bottom: 20px;
+  // ContentCard 接管 background, border-radius, padding, box-shadow, margin-bottom
 }
 
 .elder-mode-header {
@@ -108,10 +102,7 @@
 }
 
 .elder-mode-preview-card {
-  background: $card;
-  border-radius: $r;
-  padding: 20px;
-  box-shadow: $shadow-sm;
+  // ContentCard 接管 background, border-radius, padding, box-shadow
 }
 
 .elder-mode-preview-sample {

apps/miniprogram/src/pages/pkg-profile/elder-mode/index.tsx

@@ -2,6 +2,8 @@ import { View, Text } from '@tarojs/components';
 import Taro from '@tarojs/taro';
 import { useUIStore } from '../../../stores/ui';
 import { useElderClass } from '../../../hooks/useElderClass';
+import PageShell from '@/components/ui/PageShell';
+import ContentCard from '@/components/ui/ContentCard';
 import './index.scss';
 
 export default function ElderMode() {
@@ -21,8 +23,8 @@ export default function ElderMode() {
   };
 
   return (
-    <View className={`elder-mode-page ${modeClass}`}>
-      <View className='elder-mode-card'>
+    <PageShell className={`elder-mode-page ${modeClass}`}>
+      <ContentCard variant="elevated" className='elder-mode-card'>
         <View className='elder-mode-header'>
           <Text className='elder-mode-icon'>老</Text>
           <View className='elder-mode-info'>
@@ -42,19 +44,19 @@ export default function ElderMode() {
             <View className='elder-mode-switch-thumb' />
           </View>
         </View>
-      </View>
+      </ContentCard>
 
       <View className='elder-mode-preview'>
         <Text className='elder-mode-preview-title'>效果预览</Text>
-        <View className='elder-mode-preview-card'>
+        <ContentCard padding="lg" className='elder-mode-preview-card'>
           <Text className={`elder-mode-preview-sample ${isElder ? 'elder-mode-preview-sample--large' : ''}`}>
             {isElder ? '长辈模式字体示例' : '标准模式字体示例'}
           </Text>
           <Text className='elder-mode-preview-note'>
             {isElder ? '字号放大 1.3 倍，间距放大 1.2 倍' : '正常字号和间距'}
           </Text>
-        </View>
+        </ContentCard>
       </View>
-    </View>
+    </PageShell>
   );
 }