统一结账押金字段为押金赔付扣除

号主修正去掉无效的其他押金扣款，仅保留押金赔付扣除；
前后端与账单文案统一，修正时 other 与 deduct 对齐。

backend/internal/modules/dispute/arbitration.go

@@ -337,7 +337,7 @@ func buildArbitrationHandoffContent(req ArbitrateRequest, settlement arbitration
 		content += "\n结算给号主：" + money.FormatWithSymbol(settlement.OwnerIncomeAmountCent)
 	}
 	if settlement.DepositDeductAmountCent > 0 {
-		content += "\n押金扣除：" + money.FormatWithSymbol(settlement.DepositDeductAmountCent)
+		content += "\n押金赔付扣除：" + money.FormatWithSymbol(settlement.DepositDeductAmountCent)
 	}
 	return content
 }

backend/internal/modules/order/checkout.go

@@ -139,7 +139,12 @@ func (r *Repository) CounterCheckout(ctx context.Context, userID uint64, orderID
 			First(&checkout).Error; err != nil {
 			return err
 		}
-		next, err := buildCheckout(order, checkout.InitiatedBy, checkoutStatusCountered, checkout.Content, req.EvidenceURLS, req.ConsumableAmountCent, req.CoinConsumedM, req.OtherAmountCent, req.DepositDeductAmountCent, true)
+		// 号主修正只认押金赔付扣除；other 与 deduct 对齐，避免双字段语义分裂
+		depositDeductCent := req.DepositDeductAmountCent
+		if depositDeductCent <= 0 && req.OtherAmountCent > 0 {
+			depositDeductCent = req.OtherAmountCent
+		}
+		next, err := buildCheckout(order, checkout.InitiatedBy, checkoutStatusCountered, checkout.Content, req.EvidenceURLS, req.ConsumableAmountCent, req.CoinConsumedM, depositDeductCent, depositDeductCent, true)
 		if err != nil {
 			return err
 		}