修复佣金错误计算的问题

internal/service/commission_calculation/service.go

@@ -141,13 +141,17 @@ func (s *Service) CalculateCostDiffCommission(ctx context.Context, order *model.
 		return nil, errors.Wrap(errors.CodeDatabaseError, err, "获取销售店铺失败")
 	}
 
-	// 卖家利润 = 实际收款 - 成本价，必须用 ActualPaidAmount 而非 TotalAmount
-	// TotalAmount 在 fix-order-price-semantics 后始终存零售价，代理自购时会错误产生佣金
-	var sellerProfit int64
-	if order.ActualPaidAmount != nil {
-		sellerProfit = *order.ActualPaidAmount - order.SellerCostPrice
-	} else {
-		sellerProfit = order.TotalAmount - order.SellerCostPrice
+	sellerProfit, shouldCalculateSellerProfit := calculateSellerProfit(order)
+	if !shouldCalculateSellerProfit {
+		s.logger.Warn("订单缺少实际支付金额，跳过终端销售代理成本价差佣金计算",
+			zap.Uint("order_id", order.ID),
+			zap.String("source", order.Source),
+			zap.String("payment_method", order.PaymentMethod),
+			zap.String("buyer_type", order.BuyerType),
+			zap.String("purchase_role", order.PurchaseRole),
+			zap.Int64("total_amount", order.TotalAmount),
+			zap.Int64("seller_cost_price", order.SellerCostPrice),
+		)
 	}
 	if sellerProfit > 0 {
 		records = append(records, &model.CommissionRecord{
@@ -232,6 +236,28 @@ func (s *Service) CalculateCostDiffCommission(ctx context.Context, order *model.
 	return records, nil
 }
 
+// calculateSellerProfit 计算终端销售代理的成本价差收益。
+// 代理钱包/代购链路必须以 actual_paid_amount 为准，禁止回退到 total_amount，
+// 否则在 total_amount 已改成零售价后会再次产生“建议售价-成本价”的错误佣金。
+func calculateSellerProfit(order *model.Order) (int64, bool) {
+	if order == nil {
+		return 0, false
+	}
+
+	if order.ActualPaidAmount != nil {
+		return *order.ActualPaidAmount - order.SellerCostPrice, true
+	}
+
+	if order.BuyerType == model.BuyerTypeAgent ||
+		order.PaymentMethod == model.PaymentMethodWallet ||
+		order.IsPurchaseOnBehalf ||
+		order.Source == constants.OrderSourceAdmin {
+		return 0, false
+	}
+
+	return order.TotalAmount - order.SellerCostPrice, true
+}
+
 func (s *Service) triggerOneTimeCommissionForCardInTx(ctx context.Context, tx *gorm.DB, order *model.Order, cardID uint) error {
 	if order.IsPurchaseOnBehalf || order.Source != constants.OrderSourceClient {
 		return nil