style: 今日健康卡片顶部标题改用健康档案的紫蓝左右渐变

- 新增 SplashPage + appReadyProvider/_BootGate：启动闸门将启动页覆盖在最上层，
  直到 auth 判定完成且今日健康卡数据就绪，遮住登录页闪现与首页对话流初始态
- auth 初始状态改为 isLoading=true，无 token 时再置 false
- values-night/styles.xml 改为亮色白底，消除深色模式下 Flutter 初始化期间的黑色窗口背景
- 带 8 秒安全兜底，避免离线时卡在启动页

health_app/android/app/src/main/res/values-night/styles.xml

@@ -1,18 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
-    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
-        <!-- Show a splash screen on the activity. Automatically removed when
-             the Flutter engine draws its first frame -->
+    <!-- 启动页强制亮色：即使系统处于深色模式，也用白底品牌图，避免黑色闪屏 -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
         <item name="android:windowBackground">@drawable/launch_background</item>
     </style>
-    <!-- Theme applied to the Android Window as soon as the process has started.
-         This theme determines the color of the Android Window while your
-         Flutter UI initializes, as well as behind your Flutter UI while its
-         running.
-
-         This Theme is only used starting with V2 of Flutter's Android embedding. -->
-    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
-        <item name="android:windowBackground">?android:colorBackground</item>
+    <!-- Flutter 引擎初始化期间的窗口背景：白底，避免深色模式下闪黑 -->
+    <style name="NormalTheme" parent="@android:style/Theme.Light.NoTitleBar">
+        <item name="android:windowBackground">@android:color/white</item>
     </style>
 </resources>

health_app/lib/app.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
@@ -5,7 +6,9 @@ import 'package:shadcn_ui/shadcn_ui.dart';
 import 'core/app_router.dart';
 import 'core/app_theme.dart';
 import 'core/navigation_provider.dart';
+import 'pages/splash_page.dart';
 import 'providers/auth_provider.dart';
+import 'providers/data_providers.dart';
 
 /// 健康管家 App 根组件
 class HealthApp extends ConsumerWidget {
@@ -25,9 +28,64 @@ class HealthApp extends ConsumerWidget {
       supportedLocales: const [Locale('zh', 'CN'), Locale('zh')],
       locale: const Locale('zh'),
       home: const _RootNavigator(),
-      // 注入 ShadTheme，让所有页面都能用 shadcn 组件
-      builder: (context, child) =>
-          ShadTheme(data: AppTheme.shadTheme, child: child!),
+      // 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
+      builder: (context, child) => ShadTheme(
+        data: AppTheme.shadTheme,
+        child: _BootGate(child: child!),
+      ),
+    );
+  }
+}
+
+/// 启动是否就绪：auth 判定完成，且（已登录的普通用户）今日健康卡数据已到位。
+/// 未登录或医生/管理员无需等待健康卡。
+final appReadyProvider = Provider<bool>((ref) {
+  final auth = ref.watch(authProvider);
+  if (auth.isLoading) return false; // 还在判登录态 → 继续盖 Splash
+  if (!auth.isLoggedIn) return true; // 未登录 → 就绪，露出登录页
+  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
+  // 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;
+});
+
+/// 启动闸门——就绪前在最上层覆盖 Splash，盖住登录页闪现与首页对话流初始态。
+/// 带 8 秒安全兜底，避免离线时数据永不返回导致卡在启动页。
+class _BootGate extends ConsumerStatefulWidget {
+  final Widget child;
+  const _BootGate({required this.child});
+
+  @override
+  ConsumerState<_BootGate> createState() => _BootGateState();
+}
+
+class _BootGateState extends ConsumerState<_BootGate> {
+  bool _timedOut = false;
+  Timer? _timer;
+
+  @override
+  void initState() {
+    super.initState();
+    _timer = Timer(const Duration(seconds: 8), () {
+      if (mounted) setState(() => _timedOut = true);
+    });
+  }
+
+  @override
+  void dispose() {
+    _timer?.cancel();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final ready = ref.watch(appReadyProvider) || _timedOut;
+    return Stack(
+      children: [
+        widget.child,
+        if (!ready) const Positioned.fill(child: SplashPage()),
+      ],
     );
   }
 }

health_app/lib/pages/home/widgets/chat_messages_view.dart

@@ -1703,7 +1703,11 @@ class ChatMessagesView extends ConsumerWidget {
             width: double.infinity,
             padding: const EdgeInsets.fromLTRB(16, 12, 16, 10),
             decoration: const BoxDecoration(
-              gradient: AppColors.drawerGradient,
+              gradient: LinearGradient(
+                begin: Alignment.centerLeft,
+                end: Alignment.centerRight,
+                colors: [Color(0xFFE0C3FC), Color(0xFF8EC5FC)],
+              ),
               borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
             ),
             child: Row(

health_app/lib/pages/splash_page.dart

@@ -0,0 +1,20 @@
+import 'package:flutter/material.dart';
+
+/// 启动页——盖在整个 App 最上层，直到「今日健康卡片」数据就绪后才撤掉，
+/// 用于遮住启动期间的登录页闪现与首页对话流初始态。始终亮色白底。
+class SplashPage extends StatelessWidget {
+  const SplashPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const ColoredBox(
+      color: Colors.white,
+      child: Center(
+        child: Image(
+          image: AssetImage('assets/branding/health_splash_master.png'),
+          fit: BoxFit.contain,
+        ),
+      ),
+    );
+  }
+}

health_app/lib/providers/auth_provider.dart

@@ -35,13 +35,18 @@ class AuthNotifier extends Notifier<AuthState> {
   @override
   AuthState build() {
     _checkAuth();
-    return const AuthState(isLoggedIn: false, isLoading: false);
+    // 初始为"加载中"，让启动闸门显示 Splash 盖住登录页/首页初始态
+    return const AuthState(isLoggedIn: false, isLoading: true);
   }
 
   Future<void> _checkAuth() async {
     final db = ref.read(localDbProvider);
     final refresh = await db.read('refresh_token');
-    if (refresh == null) return; // 无token，保持 isLoggedIn: false
+    if (refresh == null) {
+      // 无 token：判定完成、未登录
+      state = const AuthState(isLoggedIn: false, isLoading: false);
+      return;
+    }
 
     state = const AuthState(isLoading: true);
     try {