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/pages/settings/settings_pages.dart

@@ -44,6 +44,11 @@ class SettingsPage extends ConsumerWidget {
               children: [
                 _SettingsGroup(
                   children: [
+                    _SettingsTile(
+                      icon: Icons.elderly_rounded,
+                      title: '长辈模式',
+                      onTap: () => pushRoute(ref, 'elderMode'),
+                    ),
                     _SettingsTile(
                       icon: LucideIcons.bluetooth,
                       title: '蓝牙设备',
@@ -272,6 +277,7 @@ class _SettingsTile extends StatelessWidget {
                   ),
                 ),
               ),
+              const SizedBox(width: 6),
               const Icon(
                 Icons.arrow_forward_ios_rounded,
                 size: 15,