refactor: 重构资产实体和DTO结构类型

将gjson.Json类型替换为具体的结构体和map类型，修正DAO层链式调用，启用SKU元数据校验逻辑

consts/stock/stock_status.go

@@ -1,21 +1,30 @@
 package stock
 
-// StockStatus 库存状态枚举
-type StockStatus int
+import "github.com/gogf/gf/v2/util/gconv"
 
-const (
-	StockStatusAvailable StockStatus = 1 // 可用，未分配渠道
-	StockStatusSold      StockStatus = 2 // 已售出
-	StockStatusReserved  StockStatus = 3 // 预留
-	StockStatusLocked    StockStatus = 4 // 锁定
+// StockStatus 库存状态枚举
+
+var (
+	StockStatusAvailable = newStockStatus(gconv.PtrInt8(1), "可用，未分配渠道")
+	StockStatusSold      = newStockStatus(gconv.PtrInt8(2), "已售出")
+	StockStatusReserved  = newStockStatus(gconv.PtrInt8(3), "预留")
+	StockStatusLocked    = newStockStatus(gconv.PtrInt8(4), "锁定")
 )
 
-// GetAllStockStatuses 获取所有库存状态
-func GetAllStockStatuses() []StockStatus {
-	return []StockStatus{
-		StockStatusAvailable,
-		StockStatusSold,
-		StockStatusReserved,
-		StockStatusLocked,
-	}
+type StockStatus *int8
+
+type stockStatus struct {
+	code StockStatus
+	desc string
+}
+
+func (s stockStatus) Code() StockStatus {
+	return s.code
+}
+func (s stockStatus) Desc() string {
+	return s.desc
+}
+
+func newStockStatus(code StockStatus, desc string) stockStatus {
+	return stockStatus{code: code, desc: desc}
 }