资产详情新增两个字段

internal/service/asset/usage_summary.go

@@ -0,0 +1,16 @@
+package asset
+
+import "github.com/break/junhong_cmp_fiber/internal/model"
+
+// computeUsageSummary 汇总当前世代套餐的虚已用量和虚剩余量。
+// 对每条记录调用 BuildTrafficMetrics() 获取虚流量字段，累加后计算剩余。
+func computeUsageSummary(usages []*model.PackageUsage) (totalUsedMB float64, totalRemainingMB float64) {
+	var totalVirtualTotal float64
+	for _, u := range usages {
+		m := u.BuildTrafficMetrics()
+		totalUsedMB += m.VirtualUsedMB
+		totalVirtualTotal += float64(m.VirtualTotalMB)
+	}
+	totalRemainingMB = totalVirtualTotal - totalUsedMB
+	return
+}