fix: 修正套餐激活和时间字段nullable问题

核心变更：
1. Model层时间字段改为*time.Time并设为nullable
   - PackageUsage.ActivatedAt/ExpiresAt
   - PersonalCustomerDevice/ICCID/Phone.LastUsedAt/VerifiedAt

2. 数据库迁移：
   - activated_at/expires_at列移除NOT NULL约束
   - 清洗零值记录(status=0且activated_at<'2000-01-01')

3. 新增ActivateSpecificPackage方法：精准激活指定套餐，
   修复HandlePackageQueueActivation从"查找过期包"改为直接激活payload指定套餐

4. 新增孤儿套餐恢复扫描：Worker启动或每次套餐检查时，
   自动发现并恢复无status=1主套餐的孤儿载体

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/polling/package_activation_handler.go

@@ -14,6 +14,7 @@ import (
 	packagepkg "github.com/break/junhong_cmp_fiber/internal/service/package"
 	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
 	"github.com/break/junhong_cmp_fiber/pkg/constants"
+	"github.com/break/junhong_cmp_fiber/pkg/errors"
 )
 
 // PackageActivationHandler 套餐激活检查处理器
@@ -94,9 +95,116 @@ func (h *PackageActivationHandler) HandlePackageActivationCheck(ctx context.Cont
 		zap.Int("processed", len(expiredPackages)),
 		zap.Duration("total_duration", time.Since(startTime)))
 
+	// 任务 6: 孤儿套餐扫描
+	orphanCount, err := h.findAndActivateOrphanPackages(ctx)
+	if err != nil {
+		h.logger.Error("孤儿套餐扫描失败", zap.Error(err))
+		// 不中断主流程
+	} else if orphanCount > 0 {
+		h.logger.Info("孤儿套餐扫描完成",
+			zap.Int("orphan_count", orphanCount))
+	}
+
 	return nil
 }
 
+// findAndActivateOrphanPackages 任务 6.1-6.2: 查找孤儿载体并触发激活
+// 孤儿定义：存在 status=0 的主套餐（pending_realname_activation=false），但不存在 status=1 的主套餐
+func (h *PackageActivationHandler) findAndActivateOrphanPackages(ctx context.Context) (int, error) {
+	// 查询孤儿待生效主套餐（无生效主套餐但有待生效主套餐）
+	var orphanUsages []*model.PackageUsage
+	err := h.db.WithContext(ctx).
+		Where("status = ?", constants.PackageUsageStatusPending).
+		Where("master_usage_id IS NULL").
+		Where("pending_realname_activation = ?", false).
+		Where("deleted_at IS NULL").
+		Limit(100).
+		Find(&orphanUsages).Error
+	if err != nil {
+		return 0, errors.Wrap(errors.CodeDatabaseError, err, "查询孤儿套餐失败")
+	}
+
+	if len(orphanUsages) == 0 {
+		return 0, nil
+	}
+
+	// 按载体分组，去重
+	type carrierKey struct {
+		carrierType string
+		carrierID   uint
+	}
+	carrierMap := make(map[carrierKey]*model.PackageUsage) // 保留 priority 最低的套餐
+
+	for _, usage := range orphanUsages {
+		key := carrierKey{}
+		if usage.IotCardID > 0 {
+			key.carrierType = "iot_card"
+			key.carrierID = usage.IotCardID
+		} else if usage.DeviceID > 0 {
+			key.carrierType = "device"
+			key.carrierID = usage.DeviceID
+		} else {
+			continue
+		}
+
+		// 检查该载体是否已有生效主套餐
+		var activeCount int64
+		var countErr error
+		if key.carrierType == "iot_card" {
+			countErr = h.db.WithContext(ctx).
+				Model(&model.PackageUsage{}).
+				Where("status = ?", constants.PackageUsageStatusActive).
+				Where("master_usage_id IS NULL").
+				Where("iot_card_id = ?", key.carrierID).
+				Count(&activeCount).Error
+		} else {
+			countErr = h.db.WithContext(ctx).
+				Model(&model.PackageUsage{}).
+				Where("status = ?", constants.PackageUsageStatusActive).
+				Where("master_usage_id IS NULL").
+				Where("device_id = ?", key.carrierID).
+				Count(&activeCount).Error
+		}
+		if countErr != nil {
+			h.logger.Warn("检查载体生效套餐失败",
+				zap.String("carrier_type", key.carrierType),
+				zap.Uint("carrier_id", key.carrierID),
+				zap.Error(countErr))
+			continue
+		}
+
+		// 已有生效套餐，跳过
+		if activeCount > 0 {
+			continue
+		}
+
+		// 保留 priority 最低的套餐
+		if existing, ok := carrierMap[key]; ok {
+			if usage.Priority < existing.Priority {
+				carrierMap[key] = usage
+			}
+		} else {
+			carrierMap[key] = usage
+		}
+	}
+
+	// 为每个孤儿载体提交激活任务
+	count := 0
+	for key, usage := range carrierMap {
+		if err := h.enqueueActivationTask(ctx, usage.ID, key.carrierType, key.carrierID, "orphan_recovery"); err != nil {
+			h.logger.Warn("提交孤儿套餐激活任务失败",
+				zap.Uint("package_usage_id", usage.ID),
+				zap.String("carrier_type", key.carrierType),
+				zap.Uint("carrier_id", key.carrierID),
+				zap.Error(err))
+			continue
+		}
+		count++
+	}
+
+	return count, nil
+}
+
 // findExpiredMainPackages 任务 19.2: 查询已过期的主套餐
 func (h *PackageActivationHandler) findExpiredMainPackages(ctx context.Context) ([]*model.PackageUsage, error) {
 	var packages []*model.PackageUsage
@@ -123,9 +231,13 @@ func (h *PackageActivationHandler) processExpiredPackage(ctx context.Context, pk
 			return err
 		}
 
+		expiresAt := time.Now()
+		if pkg.ExpiresAt != nil {
+			expiresAt = *pkg.ExpiresAt
+		}
 		h.logger.Info("主套餐已过期",
 			zap.Uint("package_usage_id", pkg.ID),
-			zap.Time("expires_at", pkg.ExpiresAt))
+			zap.Time("expires_at", expiresAt))
 
 		// 任务 19.4: 加油包级联失效
 		if err := h.invalidateAddons(ctx, tx, pkg.ID); err != nil {
@@ -422,23 +534,17 @@ func (h *PackageActivationHandler) HandlePackageQueueActivation(ctx context.Cont
 
 	// 调用 ActivationService 执行激活
 	if h.activationService != nil {
-		if err := h.activationService.ActivateQueuedPackage(ctx, payload.CarrierType, payload.CarrierID); err != nil {
+		if err := h.activationService.ActivateSpecificPackage(ctx, payload.PackageUsageID); err != nil {
 			h.logger.Error("套餐激活失败",
 				zap.Uint("package_usage_id", payload.PackageUsageID),
-				zap.String("carrier_type", payload.CarrierType),
-				zap.Uint("carrier_id", payload.CarrierID),
 				zap.Error(err))
 			return err
 		}
 	} else {
-		// ActivationService 未注入，直接更新状态
-		now := time.Now()
-		if err := h.db.Model(&pkg).Updates(map[string]interface{}{
-			"status":       constants.PackageUsageStatusActive,
-			"activated_at": now,
-		}).Error; err != nil {
-			return err
-		}
+		// ActivationService 未注入，无法安全激活（缺少 expires_at 计算）
+		h.logger.Error("激活服务未注入，无法执行套餐激活",
+			zap.Uint("package_usage_id", payload.PackageUsageID))
+		return errors.New(errors.CodeInternalError, "激活服务未注入，无法执行套餐激活")
 	}
 
 	h.logger.Info("套餐激活成功",