feat: 二级页面色彩刷新 + 用药/通知/设备重构 + 后端健康档案/通知管线增强 + 大量测试

## 后端
- 健康档案: 新增手术状态字段 + EF 迁移; HealthArchiveService 新增查询方法
- 健康记录: HealthRecordService 新增批量/统计方法; 契约扩展
- 用药: 新增 MedicationScheduleStatus 枚举; MedicationService 排班逻辑调整
- 通知: EfUserNotificationPipeline 重构; 新增 EfReminderCatchUpService; 通知管线支持更多场景
- 用户: UserService 账号删除逻辑; 新增 local_account_file_cleanup; EfUserRepository 扩展
- AI: medication_agent_handler 微调; prompt_manager 优化; AiConversationService 上下文处理
- Endpoint: doctor/medication/exercise/health/notification/user 等多接口调整
- BackgroundService: health_record_reminder_service 重构, 提醒补漏逻辑
- 测试: 新增 account_deletion/doctor_endpoint/medication_schedule/medication_update/prompt_manager 测试

## 前端
- UI 系统: app_theme 大幅重构; app_colors/app_design_tokens/app_module_visuals 调整; 二级页面色彩刷新
- 主页: home_page 背景渐变 + 消息列表提取 _HomeMessages + 通知检查逻辑; chat_messages_view 全面重构
- 用药: medication_list/edit/checkin 三页重构, 新增 medication_ui_logic 抽取
- 通知: notification_prefs_page 重构, 新增 notification_prefs_logic; notification_center 优化
- 设备: device_management 重构, 新增 device_sync_ui_logic; device_scan 优化
- 趋势图: trend_page 大幅重构
- 登录: login_page 重构
- 个人资料: 新增 profile_edit_page; profile_page 优化
- 运动: 新增 exercise/ 目录 + care_plan_ui_logic
- 其他: remaining_pages/report_pages/health_drawer/admin/doctor 等多页面调整
- 组件: common_widgets/app_empty_state/app_error_state/app_future_view/app_toast/ai_content 优化
- Provider: chat_provider/consultation_provider/data_providers/auth_provider 调整
- AndroidManifest: 移除多余权限
- 测试: 新增 ai_content/care_plan/home_message/login_flow/medication_checkin/medication_ui/notification_prefs/profile_device/secondary_page/swipe_delete 等大量测试

## 文档
- 新增 ui-design-system.md 设计系统文档
- 新增 secondary-page-color-refresh 计划 + specs 目录

health_app/lib/pages/diet/diet_capture_page.dart

@@ -9,6 +9,8 @@ import '../../core/app_design_tokens.dart';
 import '../../core/app_theme.dart';
 import '../../providers/auth_provider.dart';
 import '../../widgets/app_toast.dart';
+import '../../widgets/common_widgets.dart';
+import '../../widgets/app_empty_state.dart';
 import 'diet_nutrition_widgets.dart';
 import 'diet_record_logic.dart';
 
@@ -321,10 +323,9 @@ class DietNotifier extends Notifier<DietState> {
   }
 }
 
-// ─────────── 饮食主题色（暖橙系，不再用紫色）───────────
+// 饮食主题色
 const _dietAccent = DietPalette.primary;
 const _dietKcalText = DietPalette.calorie;
-const _dietGradient = DietPalette.gradient;
 
 class DietCapturePage extends ConsumerStatefulWidget {
   const DietCapturePage({super.key});
@@ -352,7 +353,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
     final state = ref.watch(dietProvider);
     return GradientScaffold(
       appBar: AppBar(
-        backgroundColor: Colors.white.withValues(alpha: 0.9),
+        backgroundColor: Colors.white,
         title: const Text(
           '饮食分析',
           style: TextStyle(fontSize: 20, fontWeight: FontWeight.w600),
@@ -425,7 +426,6 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
       decoration: BoxDecoration(
         color: Colors.white,
         borderRadius: AppRadius.xlBorder,
-        boxShadow: AppColors.cardShadowLight,
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -480,7 +480,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
     );
   }
 
-  // ─────────── 分析中 ───────────
+  // 分析中
   Widget _buildAnalyzing(DietState state) {
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 40),
@@ -503,7 +503,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
             const SizedBox(height: 8),
             Text(
               state.errorMessage!,
-              style: const TextStyle(fontSize: 14, color: AppColors.error),
+              style: const TextStyle(fontSize: 14, color: AppColors.errorText),
               textAlign: TextAlign.center,
             ),
           ],
@@ -513,43 +513,15 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
   }
 
   Widget _buildNoFoodHint() {
-    return Container(
-      width: double.infinity,
-      padding: const EdgeInsets.symmetric(vertical: 36, horizontal: 18),
-      decoration: BoxDecoration(
-        color: Colors.white,
-        borderRadius: BorderRadius.circular(18),
-        border: Border.all(color: AppColors.borderLight),
-        boxShadow: AppColors.cardShadowLight,
-      ),
-      child: Column(
-        children: [
-          const Icon(
-            Icons.image_not_supported_outlined,
-            size: 44,
-            color: AppColors.textHint,
-          ),
-          const SizedBox(height: 14),
-          const Text(
-            '未识别到食物',
-            style: TextStyle(
-              fontSize: 16,
-              fontWeight: FontWeight.w700,
-              color: AppColors.textPrimary,
-            ),
-          ),
-          const SizedBox(height: 6),
-          const Text(
-            '请重新拍摄或选择含有食物的清晰照片',
-            textAlign: TextAlign.center,
-            style: TextStyle(fontSize: 13, color: AppColors.textSecondary),
-          ),
-        ],
-      ),
+    return AppEmptyState(
+      icon: Icons.image_not_supported_outlined,
+      iconColor: _dietAccent,
+      title: '未识别到食物',
+      subtitle: '请重新拍摄或选择含有食物的清晰照片',
     );
   }
 
-  // ─────────── 食物列表 ───────────
+  // 食物列表
   Widget _buildFoodList(WidgetRef ref) {
     final state = ref.watch(dietProvider);
     return Container(
@@ -557,7 +529,6 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
       decoration: BoxDecoration(
         color: Colors.white,
         borderRadius: AppRadius.xlBorder,
-        boxShadow: AppColors.cardShadowLight,
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -618,8 +589,9 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                   height: 26,
                   alignment: Alignment.center,
                   decoration: BoxDecoration(
-                    gradient: food.selected ? _dietGradient : null,
-                    color: food.selected ? null : DietPalette.primarySoft,
+                    color: food.selected
+                        ? AppColors.primary
+                        : AppColors.primarySoft,
                     borderRadius: AppRadius.smBorder,
                     border: Border.all(
                       color: food.selected
@@ -751,7 +723,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
     return c;
   }
 
-  // ─────────── AI 点评 ───────────
+  // AI 点评
   Widget _buildAiCommentary(String? text) {
     final hasText = text != null && text.trim().isNotEmpty;
     return Container(
@@ -759,7 +731,6 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
       decoration: BoxDecoration(
         color: Colors.white,
         borderRadius: AppRadius.xlBorder,
-        boxShadow: AppColors.cardShadowLight,
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -770,8 +741,8 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                 width: 4,
                 height: 18,
                 decoration: BoxDecoration(
-                  gradient: _dietGradient,
-                  borderRadius: BorderRadius.circular(999),
+                  color: _dietAccent,
+                  borderRadius: AppRadius.pillBorder,
                 ),
               ),
               const SizedBox(width: 9),
@@ -816,31 +787,9 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
         top: false,
         child: Padding(
           padding: const EdgeInsets.fromLTRB(16, 10, 16, 12),
-          child: GestureDetector(
-            onTap: _saveDietRecord,
-            child: Container(
-              height: 50,
-              alignment: Alignment.center,
-              decoration: BoxDecoration(
-                gradient: _dietGradient,
-                borderRadius: AppRadius.mdBorder,
-                boxShadow: [
-                  BoxShadow(
-                    color: _dietAccent.withValues(alpha: 0.24),
-                    blurRadius: 14,
-                    offset: const Offset(0, 7),
-                  ),
-                ],
-              ),
-              child: const Text(
-                '保存记录',
-                style: TextStyle(
-                  fontSize: 16,
-                  fontWeight: FontWeight.w900,
-                  color: Colors.white,
-                ),
-              ),
-            ),
+          child: AppGradientOutlineButton(
+            label: '保存记录',
+            onPressed: _saveDietRecord,
           ),
         ),
       ),