已完成用户APP首期功能开发

交付用户端首期页面、配套接口、后台资源及测试文档。用户APP构建、静态分析和三个管理后台构建通过；完整测试仍有2项失败，后端模型注释检查未通过，详见交付记录。

backend/api/internal/logic/common/resource.go

@@ -315,6 +315,13 @@ func ValidateResourceValues(model any, values map[string]any, creating bool) err
 		if !positive("amount") || !nonEmpty("channel") {
 			return errors.New("invalid payment")
 		}
+	case *models.DevUsageStat:
+		source, sourceExists := values["source"].(string)
+		allowedSource := source == "meter" || source == "device" || source == "manual"
+		if !nonNegative("usage_kg") || !nonNegative("breakfast_kg") || !nonNegative("lunch_kg") || !nonNegative("dinner_kg") ||
+			!nonEmpty("stat_date") || !nonEmpty("calc_version") || !nonEmpty("calculated_at") || (sourceExists && !allowedSource) || (creating && !sourceExists) {
+			return errors.New("invalid usage statistic")
+		}
 	}
 	return nil
 }