feat: 长辈模式（大字大按钮 + 偏好按账号隔离）+ 语音输入（按住说话 + 实时转写 + 后端代理 DashScope ASR + 患者端专用）+ 健康仪表盘背景渐变

health_app/lib/app.dart

@@ -5,10 +5,12 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shadcn_ui/shadcn_ui.dart';
 import 'core/app_router.dart';
 import 'core/app_theme.dart';
+import 'core/elder_mode_scope.dart';
 import 'core/navigation_provider.dart';
 import 'pages/splash_page.dart';
 import 'providers/auth_provider.dart';
 import 'providers/data_providers.dart';
+import 'providers/elder_mode_provider.dart';
 
 /// 健康管家 App 根组件
 class HealthApp extends ConsumerWidget {
@@ -16,10 +18,16 @@ class HealthApp extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
+    final auth = ref.watch(authProvider);
+    final elderMode = ref.watch(elderModeProvider);
+    final isPatient = auth.isLoggedIn && auth.user?.role == 'User';
+    final useElderMode = isPatient && elderMode.isEnabled;
+    final useLargeText = useElderMode && elderMode.preferences.largeTextEnabled;
+
     return MaterialApp(
       title: '小脉健康',
       debugShowCheckedModeBanner: false,
-      theme: AppTheme.lightTheme,
+      theme: useElderMode ? AppTheme.elderLightTheme : AppTheme.lightTheme,
       localizationsDelegates: const [
         GlobalMaterialLocalizations.delegate,
         GlobalWidgetsLocalizations.delegate,
@@ -30,12 +38,23 @@ class HealthApp extends ConsumerWidget {
       home: const _RootNavigator(),
       // 注入 ShadTheme + 启动闸门：Splash 盖在最上层，直到首页今日健康卡数据就绪
       // 外层包一层 GestureDetector：点击任意空白处取消输入框焦点（全 app 生效）
-      builder: (context, child) => ShadTheme(
-        data: AppTheme.shadTheme,
-        child: GestureDetector(
-          behavior: HitTestBehavior.translucent,
-          onTap: () => FocusManager.instance.primaryFocus?.unfocus(),
-          child: _BootGate(child: child!),
+      builder: (context, child) => ElderModeScope(
+        enabled: useElderMode,
+        largeTextEnabled: useLargeText,
+        child: Builder(
+          builder: (scopeContext) => MediaQuery(
+            data: MediaQuery.of(
+              scopeContext,
+            ).copyWith(textScaler: ElderModeScope.textScalerFor(scopeContext)),
+            child: ShadTheme(
+              data: AppTheme.shadTheme,
+              child: GestureDetector(
+                behavior: HitTestBehavior.translucent,
+                onTap: () => FocusManager.instance.primaryFocus?.unfocus(),
+                child: _BootGate(child: child!),
+              ),
+            ),
+          ),
         ),
       ),
     );
@@ -52,6 +71,7 @@ final appReadyProvider = Provider<bool>((ref) {
   if (currentRoute == 'login') return false; // 等根导航切到已登录首页后再撤 Splash
   final role = auth.user?.role ?? 'User';
   if (role != 'User') return true; // 医生/管理员首页不依赖今日健康卡
+  if (!ref.watch(elderModeProvider).isLoaded) return false;
   // 普通用户：等今日健康卡片数据（成功或失败都算就绪，避免卡死）
   final health = ref.watch(latestHealthProvider);
   return health.hasValue || health.hasError;