fix: 图片发送/医生加载/运动超时/用药黑屏/服药打卡

- sendImage: 本地预览→上传→远程URL替换
- doctorListProvider: 8s超时+mock医生fallback
- currentExercisePlanProvider: 8s超时→显示空状态
- 用药编辑: try-catch防黑屏+刷新列表
- 服药打卡: 接入后端confirm()接口

health_app/lib/pages/settings/settings_pages.dart

@@ -9,8 +9,14 @@ class SettingsPage extends ConsumerWidget {
   @override Widget build(BuildContext context, WidgetRef ref) {
     return Scaffold(
       backgroundColor: const Color(0xFFF8F7FF),
+      appBar: AppBar(
+        backgroundColor: Colors.white,
+        elevation: 0,
+        leading: IconButton(icon: const Icon(Icons.chevron_left), onPressed: () => popRoute(ref)),
+        title: const Text('设置', style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: Color(0xFF1A1A1A))),
+        centerTitle: true,
+      ),
       body: SafeArea(child: SingleChildScrollView(padding: const EdgeInsets.only(bottom: 30), child: Column(children: [
-        Container(width: double.infinity, padding: const EdgeInsets.all(24), decoration: const BoxDecoration(color: Colors.white, borderRadius: BorderRadius.only(bottomLeft: Radius.circular(24), bottomRight: Radius.circular(24))), child: Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [Text('9:41', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: Colors.grey[800])), Row(children: [Icon(Icons.wifi, size: 18, color: Colors.grey[700]), const SizedBox(width: 4), Icon(Icons.battery_full, size: 18, color: Colors.grey[700])]),])),
         const SizedBox(height: 12),
         _SetItem(icon: Icons.notifications_outlined, title: '消息通知', onTap: () => pushRoute(ref, 'notificationPrefs')),
         _SetItem(icon: Icons.medication_outlined, title: '用药提醒', subtitle: 'mmHg / mmol/L', onTap: () => pushRoute(ref, 'medications')),