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/widgets/health_drawer.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shadcn_ui/shadcn_ui.dart';
 import '../core/app_colors.dart';
 import '../core/app_design_tokens.dart';
+import '../core/elder_mode_scope.dart';
 import '../core/app_module_visuals.dart';
 import '../core/navigation_provider.dart';
 import '../providers/auth_provider.dart';
@@ -307,11 +308,12 @@ class _MetricTile extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final elderMode = ElderModeScope.enabledOf(context);
     return InkWell(
       onTap: onTap,
       borderRadius: BorderRadius.circular(18),
       child: Container(
-        height: 100,
+        height: elderMode ? 112 : 100,
         padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 10),
         decoration: BoxDecoration(
           color: Colors.white.withValues(alpha: 0.22),
@@ -368,6 +370,7 @@ class _NavigationSection extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final elderMode = ElderModeScope.enabledOf(context);
     final items = [
       _NavItem(
         icon: LucideIcons.folderHeart,
@@ -426,15 +429,19 @@ class _NavigationSection extends StatelessWidget {
         itemCount: items.length,
         shrinkWrap: true,
         physics: const NeverScrollableScrollPhysics(),
-        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
-          crossAxisCount: 4,
-          mainAxisExtent: 82,
-          mainAxisSpacing: 7,
-          crossAxisSpacing: 8,
+        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+          crossAxisCount: elderMode ? 2 : 4,
+          mainAxisExtent: elderMode ? 82 : 82,
+          mainAxisSpacing: elderMode ? 10 : 7,
+          crossAxisSpacing: elderMode ? 10 : 8,
         ),
         itemBuilder: (context, index) {
           final item = items[index];
-          return _NavTile(item: item, onTap: () => pushRoute(ref, item.route));
+          return _NavTile(
+            item: item,
+            elderMode: elderMode,
+            onTap: () => pushRoute(ref, item.route),
+          );
         },
       ),
     );
@@ -443,8 +450,13 @@ class _NavigationSection extends StatelessWidget {
 
 class _NavTile extends StatelessWidget {
   final _NavItem item;
+  final bool elderMode;
   final VoidCallback onTap;
-  const _NavTile({required this.item, required this.onTap});
+  const _NavTile({
+    required this.item,
+    required this.elderMode,
+    required this.onTap,
+  });
 
   String get _title => switch (item.route) {
     'healthArchive' => '健康档案',
@@ -473,6 +485,54 @@ class _NavTile extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final isDevice = item.route == 'devices';
+    if (elderMode) {
+      return InkWell(
+        onTap: onTap,
+        borderRadius: AppRadius.lgBorder,
+        child: Container(
+          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
+          decoration: BoxDecoration(
+            color: const Color(0xFFF8F8FC),
+            borderRadius: AppRadius.lgBorder,
+            border: Border.all(color: const Color(0xFFE7E8F0)),
+          ),
+          child: Row(
+            children: [
+              Container(
+                width: 54,
+                height: 54,
+                decoration: BoxDecoration(
+                  color: isDevice ? AppColors.device : null,
+                  gradient: isDevice
+                      ? null
+                      : LinearGradient(
+                          begin: Alignment.topLeft,
+                          end: Alignment.bottomRight,
+                          colors: _colors,
+                        ),
+                  borderRadius: AppRadius.mdBorder,
+                ),
+                child: Icon(item.icon, color: Colors.white, size: 29),
+              ),
+              const SizedBox(width: 10),
+              Expanded(
+                child: Text(
+                  _title,
+                  maxLines: 2,
+                  overflow: TextOverflow.ellipsis,
+                  style: const TextStyle(
+                    fontSize: 17,
+                    fontWeight: FontWeight.w700,
+                    color: AppColors.textPrimary,
+                    height: 1.15,
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ),
+      );
+    }
     return InkWell(
       onTap: onTap,
       borderRadius: AppRadius.mdBorder,
@@ -635,23 +695,13 @@ class _HealthDashboardBackgroundPainter extends CustomPainter {
   @override
   void paint(Canvas canvas, Size size) {
     final rect = Offset.zero & size;
-    canvas.drawRect(rect, Paint()..color = const Color(0xFFBAE6FD));
-
-    void drawGlow(Alignment center, Color color) {
-      final paint = Paint()
-        ..shader = RadialGradient(
-          center: center,
-          radius: 1,
-          colors: [color, color.withValues(alpha: 0)],
-          stops: const [0, 0.8],
-        ).createShader(rect);
-      canvas.drawRect(rect, paint);
-    }
-
-    drawGlow(Alignment.bottomRight, const Color(0xFF818CF8));
-    drawGlow(const Alignment(0, 0.6), const Color(0xFF60A5FA));
-    drawGlow(const Alignment(0.6, -0.6), const Color(0xFF6366F1));
-    drawGlow(const Alignment(-0.6, -0.6), const Color(0xFF38BDF8));
+    final paint = Paint()
+      ..shader = const LinearGradient(
+        begin: Alignment.topLeft,
+        end: Alignment.bottomRight,
+        colors: [Color(0xFF00C6FB), Color(0xFF005BEA)],
+      ).createShader(rect);
+    canvas.drawRect(rect, paint);
   }
 
   @override