fix(miniprogram): 关怀模式非线性放大重构 + 3 页面接入

- elder-mode.scss: 等比×1.3改为非线性放大（标题×1.15/正文×1.35/辅助×1.55）
- 体征网格从2列改为1列，解决放大后溢出问题
- 行高从1.5提升到1.7，对比度$tx3→$tx2增强可读性
- 健康页/消息页/咨询页接入useUIStore关怀模式
- 共享组件(EmptyState/ErrorState/Loading/StepIndicator)适配关怀模式
- 触控区域统一提升到56px+

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

apps/miniprogram/src/pages/messages/index.tsx

@@ -6,6 +6,7 @@ import { notificationService } from '../../services/notification';
 import Loading from '../../components/Loading';
 import GuestGuard from '../../components/GuestGuard';
 import { useAuthStore } from '../../stores/auth';
+import { useUIStore } from '../../stores/ui';
 import './index.scss';
 
 type MsgTab = 'consultation' | 'notification';
@@ -29,6 +30,8 @@ const NOTIFY_ICONS: Record<string, { icon: string; bg: string; color: string }>
 
 export default function Messages() {
   const user = useAuthStore((s) => s.user);
+  const { mode } = useUIStore();
+  const modeClass = mode === 'elder' ? 'elder-mode' : '';
   const [activeTab, setActiveTab] = useState<MsgTab>('consultation');
   const [sessions, setSessions] = useState<ConsultationSession[]>([]);
   const [notifications, setNotifications] = useState<NotificationItem[]>([]);
@@ -108,7 +111,7 @@ export default function Messages() {
   const unreadConsultCount = sessions.filter((s) => s.unread_count_patient > 0).length;
 
   return (
-    <View className='messages-page'>
+    <View className={`messages-page ${modeClass}`}>
       {/* 页头 */}
       <View className='messages-header'>
         <Text className='messages-title'>消息</Text>