feat: 给 PackageUsage 添加 package_name 快照字段，修复企业卡列表 carrier_name/package_name 为空问题

- 迁移 000099：tb_package_usage 新增 package_name 列，回填历史数据
- PackageUsage model 添加 PackageName 字段（与 DataResetCycle 保持一致的快照设计）
- 4 处 PackageUsage 创建点补充 PackageName 快照（order/service.go + auto_purchase.go）
- EnterpriseCard ListCards：carrier_name 直接取 card.CarrierName，package_name 通过
  DISTINCT ON 批量查当前生效主套餐，单次查询覆盖整页，无 N+1

internal/model/package.go

@@ -77,6 +77,7 @@ type PackageUsage struct {
 	MasterUsageID             *uint      `gorm:"column:master_usage_id;type:bigint;index:idx_package_usage_master_usage_id;comment:主套餐使用记录ID(加油包关联主套餐,主套餐此字段为NULL)" json:"master_usage_id"`
 	HasIndependentExpiry      bool       `gorm:"column:has_independent_expiry;type:boolean;default:false;comment:加油包是否有独立有效期(true-有独立到期时间 false-跟随主套餐)" json:"has_independent_expiry"`
 	PendingRealnameActivation bool       `gorm:"column:pending_realname_activation;type:boolean;default:false;comment:是否等待实名激活(true-待实名后激活 false-已激活或不需实名)" json:"pending_realname_activation"`
+	PackageName               string     `gorm:"column:package_name;type:varchar(255);not null;default:'';comment:套餐名称快照(从Package复制,用于历史记录展示)" json:"package_name"`
 	DataResetCycle            string     `gorm:"column:data_reset_cycle;type:varchar(20);comment:流量重置周期(从Package复制,用于历史记录)" json:"data_reset_cycle"`
 	LastResetAt               *time.Time `gorm:"column:last_reset_at;comment:最后一次流量重置时间" json:"last_reset_at"`
 	NextResetAt               *time.Time `gorm:"column:next_reset_at;index:idx_package_usage_next_reset_at;comment:下次流量重置时间(用于定时任务查询)" json:"next_reset_at"`

internal/service/enterprise_card/service.go

@@ -288,6 +288,13 @@ func (s *Service) ListCards(ctx context.Context, enterpriseID uint, req *dto.Ent
 		return nil, errors.Wrap(errors.CodeInternalError, err, "查询卡列表失败")
 	}
 
+	// 批量查询各卡当前生效的主套餐名称（取 package_name 快照，避免 JOIN tb_package）
+	pageCardIDs := make([]uint, 0, len(cards))
+	for _, card := range cards {
+		pageCardIDs = append(pageCardIDs, card.ID)
+	}
+	packageNameMap := s.buildPackageNameMap(ctx, pageCardIDs)
+
 	items := make([]dto.EnterpriseCardItem, 0, len(cards))
 	for _, card := range cards {
 		items = append(items, dto.EnterpriseCardItem{
@@ -295,6 +302,8 @@ func (s *Service) ListCards(ctx context.Context, enterpriseID uint, req *dto.Ent
 			ICCID:             card.ICCID,
 			MSISDN:            card.MSISDN,
 			CarrierID:         card.CarrierID,
+			CarrierName:       card.CarrierName,
+			PackageName:       packageNameMap[card.ID],
 			Status:            card.Status,
 			StatusName:        getCardStatusName(card.Status),
 			NetworkStatus:     card.NetworkStatus,
@@ -310,6 +319,36 @@ func (s *Service) ListCards(ctx context.Context, enterpriseID uint, req *dto.Ent
 	}, nil
 }
 
+// buildPackageNameMap 批量查询卡列表当前生效主套餐名称，返回 map[iotCardID]packageName
+func (s *Service) buildPackageNameMap(ctx context.Context, cardIDs []uint) map[uint]string {
+	result := make(map[uint]string, len(cardIDs))
+	if len(cardIDs) == 0 {
+		return result
+	}
+
+	type usageRow struct {
+		IotCardID   uint   `gorm:"column:iot_card_id"`
+		PackageName string `gorm:"column:package_name"`
+	}
+
+	// 每张卡取优先级最低（数字最小）的生效中主套餐，使用 DISTINCT ON 保证每卡仅一条
+	var rows []usageRow
+	s.db.WithContext(ctx).Raw(`
+		SELECT DISTINCT ON (iot_card_id) iot_card_id, package_name
+		FROM tb_package_usage
+		WHERE iot_card_id IN ?
+		  AND status = 1
+		  AND master_usage_id IS NULL
+		  AND deleted_at IS NULL
+		ORDER BY iot_card_id, priority ASC
+	`, cardIDs).Scan(&rows)
+
+	for _, row := range rows {
+		result[row.IotCardID] = row.PackageName
+	}
+	return result
+}
+
 func (s *Service) SuspendCard(ctx context.Context, enterpriseID, cardID uint) error {
 	return s.updateCardNetworkStatus(ctx, enterpriseID, cardID, 0)
 }

internal/service/order/service.go

@@ -1910,6 +1910,7 @@ func (s *Service) activateMainPackage(ctx context.Context, tx *gorm.DB, order *m
 		},
 		OrderID:                   order.ID,
 		PackageID:                 pkg.ID,
+		PackageName:               pkg.PackageName,
 		UsageType:                 order.OrderType,
 		DataLimitMB:               pkg.RealDataMB,
 		Status:                    status,
@@ -1988,6 +1989,7 @@ func (s *Service) activateAddonPackage(ctx context.Context, tx *gorm.DB, order *
 		},
 		OrderID:        order.ID,
 		PackageID:      pkg.ID,
+		PackageName:    pkg.PackageName,
 		UsageType:      order.OrderType,
 		DataLimitMB:    pkg.RealDataMB,
 		Status:         status,

internal/task/auto_purchase.go

@@ -440,6 +440,7 @@ func (h *AutoPurchaseHandler) activateMainPackage(
 		},
 		OrderID:                   order.ID,
 		PackageID:                 pkg.ID,
+		PackageName:               pkg.PackageName,
 		UsageType:                 order.OrderType,
 		DataLimitMB:               pkg.RealDataMB,
 		Status:                    status,
@@ -510,6 +511,7 @@ func (h *AutoPurchaseHandler) activateAddonPackage(
 		},
 		OrderID:        order.ID,
 		PackageID:      pkg.ID,
+		PackageName:    pkg.PackageName,
 		UsageType:      order.OrderType,
 		DataLimitMB:    pkg.RealDataMB,
 		Status:         constants.PackageUsageStatusActive,

migrations/000099_add_package_name_to_package_usage.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE tb_package_usage
+DROP COLUMN IF EXISTS package_name;

migrations/000099_add_package_name_to_package_usage.up.sql

@@ -0,0 +1,15 @@
+-- 给 tb_package_usage 添加 package_name 快照字段
+-- 用于展示套餐名称，避免每次展示时都需要 JOIN tb_package 表
+-- 与 data_reset_cycle 字段保持一致的快照设计
+
+ALTER TABLE tb_package_usage
+ADD COLUMN IF NOT EXISTS package_name VARCHAR(255) NOT NULL DEFAULT '';
+
+COMMENT ON COLUMN tb_package_usage.package_name IS '套餐名称快照（创建时从 tb_package 复制，用于历史记录展示）';
+
+-- 回填历史数据：从 tb_package 表取套餐名称
+UPDATE tb_package_usage pu
+SET package_name = COALESCE(p.package_name, '')
+FROM tb_package p
+WHERE pu.package_id = p.id
+  AND pu.package_name = '';