fix(listing): 外部上传按后台实时配置归类皮肤与折算消耗品，并补齐新增消耗品字段

- 皮肤归类：删除代码内硬编码的 externalSkinCatalog 快照，改为读取 listing.publish_options。
  修复运营在后台新增皮肤后，上传的商品被归入 other 的问题（详情页显示“其他皮肤”、
  按刀皮/金皮/红皮/武器皮分组筛选搜不到）
- 消耗品折算：externalResources 改为按 publish_options.quantity_items 生成条目与单价，
  修复 AWM 子弹按 0.6 元/发旧价折算等价格漂移（线上已调为 0.7 元/发）
- 上传契约：ExternalUploadInventory 新增 level6Ammo/barrettAmmo/gridCard9/redPacket45/
  coffeeBean/bulletPart 六个字段，字段名与消耗品 key 对齐；后续后台再新增消耗品，
  按同样 key 登记即可被上传链路识别
- 数量为 0 的消耗品不再写入资源清单，与网站自身发布流程（filter quantity > 0）保持一致
- 客服调整外部商品同样改用实时单价；Service 增加 externalPublishOptions 统一读配置并带默认值
- 验证：新增回归测试 TestExternalAccountToCreateRequestFollowsPublishOptions；
  并以线上 mobile-home-config 的真实配置 + 上传工具产出的 JSON 做跨仓库联调，
  确认“重塑→近战皮肤、骇爪-骇客少女→干员金皮”，9 项消耗品全部按线上单价生成

backend/internal/modules/listing/external_adjustment.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"hfb_sys/backend/internal/model"
+	"hfb_sys/backend/internal/modules/systemconfig"
 
 	"gorm.io/gorm"
 )
@@ -56,7 +57,9 @@ func (s *Service) AdjustExternalListing(
 	if err != nil {
 		return nil, err
 	}
-	return s.repo.AdjustExternalListing(ctx, adminID, listingID, req, config, meta)
+	// 消耗品单价同样取自后台实时配置，避免调整后的价格与网站现行单价不一致。
+	quantityItems := s.externalPublishOptions(ctx).QuantityItems
+	return s.repo.AdjustExternalListing(ctx, adminID, listingID, req, config, quantityItems, meta)
 }
 
 func (r *Repository) AdjustExternalListing(
@@ -65,6 +68,7 @@ func (r *Repository) AdjustExternalListing(
 	listingID uint64,
 	req AdminExternalListingAdjustRequest,
 	config salePriceConfig,
+	quantityItems []systemconfig.PublishQuantityItem,
 	meta AuditMeta,
 ) (*ListingDTO, error) {
 	if r == nil || r.db == nil {
@@ -105,7 +109,7 @@ func (r *Repository) AdjustExternalListing(
 		}
 
 		before := externalAdjustmentAuditSnapshot(account, listing, summary, breakdown)
-		adjustment, err := calculateExternalListingAdjustment(req, summary, referenceRatio, config)
+		adjustment, err := calculateExternalListingAdjustment(req, summary, referenceRatio, config, quantityItems)
 		if err != nil {
 			return err
 		}
@@ -179,6 +183,7 @@ func calculateExternalListingAdjustment(
 	summary map[string]any,
 	referenceRatio float64,
 	config salePriceConfig,
+	quantityItems []systemconfig.PublishQuantityItem,
 ) (externalAdjustmentResult, error) {
 	coinM := float64(req.HafCoinAmount) / 1000000
 	coinWan := float64(req.HafCoinAmount) / 10000
@@ -207,7 +212,7 @@ func calculateExternalListingAdjustment(
 		AWMBullets:    req.AWMBullets,
 		Level6Helmets: req.Level6Helmets,
 		Level6Armor:   req.Level6Armor,
-	})
+	}, quantityItems)
 	resources := mergeExternalCoreResources(summary, coreResources)
 	consumablePrice := consumableValue(map[string]any{"resources": resources})
 	sellerTotalPrice := roundMoney(sellerCoinPrice + consumablePrice)