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/providers/conversation_history_provider.dart

@@ -35,7 +35,6 @@ class ConversationHistoryNotifier
     extends AsyncNotifier<List<ConversationListItem>> {
   @override
   Future<List<ConversationListItem>> build() {
-    ref.watch(chatProvider.select((state) => state.conversationId));
     return _fetch();
   }
 
@@ -43,11 +42,9 @@ class ConversationHistoryNotifier
     final api = ref.read(apiClientProvider);
     final res = await api.get('/api/ai/conversations');
     final raw = (res.data['data'] as List?) ?? const [];
-    final currentConversationId = ref.read(chatProvider).conversationId;
     return raw
         .whereType<Map>()
         .map((m) => ConversationListItem.fromJson(Map<String, dynamic>.from(m)))
-        .where((item) => item.id != currentConversationId)
         .toList();
   }
 
@@ -56,21 +53,16 @@ class ConversationHistoryNotifier
     state = await AsyncValue.guard(_fetch);
   }
 
-  /// 删除单条；先乐观更新 UI，失败回滚。
+  /// 删除单条；后端确认成功后再更新 UI。
   Future<void> deleteOne(String id) async {
     final previous = state.asData?.value ?? const <ConversationListItem>[];
+    final api = ref.read(apiClientProvider);
+    await api.delete('/api/ai/conversations/$id');
     state = AsyncValue.data(previous.where((e) => e.id != id).toList());
-    try {
-      final api = ref.read(apiClientProvider);
-      await api.delete('/api/ai/conversations/$id');
-    } catch (_) {
-      state = AsyncValue.data(previous);
-      rethrow;
-    }
     // 同步清掉当前 chat state（如果删的就是当前会话）
     final chat = ref.read(chatProvider);
     if (chat.conversationId == id) {
-      ref.read(chatProvider.notifier).resetSession();
+      await ref.read(chatProvider.notifier).resetSession();
     }
   }
 
@@ -79,7 +71,7 @@ class ConversationHistoryNotifier
     final api = ref.read(apiClientProvider);
     final res = await api.delete('/api/ai/conversations');
     state = const AsyncValue.data([]);
-    ref.read(chatProvider.notifier).resetSession();
+    await ref.read(chatProvider.notifier).resetSession();
     final deleted = res.data['data']?['deleted'];
     return deleted is num ? deleted.toInt() : 0;
   }