feat: 新增数据库迁移，重命名 device_no 为 virtual_no，新增 iot_card.virtual_no 和 package.virtual_ratio 字段

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/service/package/service.go

@@ -126,9 +126,9 @@ func (s *Service) Create(ctx context.Context, req *dto.CreatePackageRequest) (*d
 	if req.EnableRealnameActivation != nil {
 		pkg.EnableRealnameActivation = *req.EnableRealnameActivation
 	} else {
-		// 默认启用实名激活
 		pkg.EnableRealnameActivation = true
 	}
+	pkg.VirtualRatio = calculateVirtualRatio(pkg.EnableVirtualData, pkg.RealDataMB, pkg.VirtualDataMB)
 	pkg.Creator = currentUserID
 
 	if err := s.packageStore.Create(ctx, pkg); err != nil {
@@ -250,6 +250,7 @@ func (s *Service) Update(ctx context.Context, id uint, req *dto.UpdatePackageReq
 		}
 	}
 
+	pkg.VirtualRatio = calculateVirtualRatio(pkg.EnableVirtualData, pkg.RealDataMB, pkg.VirtualDataMB)
 	pkg.Updater = currentUserID
 
 	if err := s.packageStore.Update(ctx, pkg); err != nil {
@@ -673,3 +674,12 @@ func formatAmount(amountFen int64) string {
 	}
 	return fmt.Sprintf("%.2f元/张", yuan)
 }
+
+// calculateVirtualRatio 计算虚流量比例
+// enable_virtual_data=true 且 virtual_data_mb>0 时 = real_data_mb/virtual_data_mb，否则 = 1.0
+func calculateVirtualRatio(enableVirtualData bool, realDataMB, virtualDataMB int64) float64 {
+	if enableVirtualData && virtualDataMB > 0 {
+		return float64(realDataMB) / float64(virtualDataMB)
+	}
+	return 1.0
+}