fix(distribution): 货架加价打通前台、下单与卖方分成

分站公开列表和详情展示当前货架加价；下单写入 base_price / shelf_markup / markup_site_id 快照并计入实付。
支付分账改用快照加价，不再误用 PlatformFeeCent；结账不退加价，事后改价不影响历史订单。

backend/internal/modules/order/lifecycle.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"hfb_sys/backend/internal/model"
@@ -57,7 +58,15 @@ func (r *Repository) Create(ctx context.Context, renterID uint64, req CreateRequ
 			return err
 		}
 		rentHours := estimateOrderDurationHours(snapshot)
+		shelfMarkupCent, markupSiteID, err := loadShelfMarkupTx(tx, req.DistributionSiteCode, listing.ID)
+		if err != nil {
+			return err
+		}
 		pricing := buildOrderPricing(listing, account)
+		basePriceCent := listing.PriceCent
+		if shelfMarkupCent > 0 {
+			pricing.RentAmountCent += shelfMarkupCent
+		}
 		distributionSite, distributionRule, err := distribution.ResolveOrderSourceTx(tx, req.DistributionSiteCode, listing.ID, account.ID, time.Now())
 		if err != nil {
 			return err
@@ -104,6 +113,9 @@ func (r *Repository) Create(ctx context.Context, renterID uint64, req CreateRequ
 			DepositFreeManualQuotaCent:  growthSnapshot.ManualDepositFreeQuotaCent,
 			DepositFreeUsedBeforeCent:   depositWaiver.UsedBeforeCent,
 			PlatformFeeCent:             pricing.PlatformFeeCent,
+			BasePriceCent:               basePriceCent,
+			ShelfMarkupCent:             shelfMarkupCent,
+			MarkupSiteID:                markupSiteID,
 			RentOriginalAmountCent:      rentOriginalAmountCent,
 			RentDiscountAmountCent:      rentDiscountAmountCent,
 			PureCoinOriginalAmountCent:  pricing.PureCoinAmountCent,
@@ -156,6 +168,32 @@ func (r *Repository) Create(ctx context.Context, renterID uint64, req CreateRequ
 	return r.FindForUser(ctx, renterID, createdID)
 }
 
+func loadShelfMarkupTx(tx *gorm.DB, siteCode string, listingID uint64) (int64, uint64, error) {
+	siteCode = strings.TrimSpace(siteCode)
+	if siteCode == "" || listingID == 0 {
+		return 0, 0, nil
+	}
+	var row struct {
+		SiteID uint64 `gorm:"column:site_id"`
+		Markup int64  `gorm:"column:markup"`
+	}
+	err := tx.Table("distribution_site_accounts AS dsa").
+		Select("dsa.site_id, COALESCE(dsa.markup_amount_cent, 0) AS markup").
+		Joins("INNER JOIN distribution_sites AS ds ON ds.id = dsa.site_id AND ds.site_code = ? AND ds.status = 'active'", siteCode).
+		Where("dsa.listing_id = ? AND dsa.display_status = 'enabled'", listingID).
+		Take(&row).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return 0, 0, nil
+		}
+		return 0, 0, err
+	}
+	if row.Markup < 0 {
+		row.Markup = 0
+	}
+	return row.Markup, row.SiteID, nil
+}
+
 func orderAccountSourceSnapshot(tx *gorm.DB, listingID uint64) (string, string, error) {
 	var upload model.ListingUpload
 	err := tx.Where("listing_id = ?", listingID).Order("id DESC").First(&upload).Error