added: Cost price adjustment

internal/application/product/dto/responses/product_responses.go

@@ -70,6 +70,12 @@ type ProductSimpleResponse struct {
 	IsSubscribed *bool                  `json:"is_subscribed,omitempty" comment:"当前用户是否已订阅"`
 }
 
+// ProductSimpleAdminResponse 管理员产品简单信息响应（包含成本价）
+type ProductSimpleAdminResponse struct {
+	ProductSimpleResponse
+	CostPrice float64 `json:"cost_price" comment:"成本价"`
+}
+
 // ProductStatsResponse 产品统计响应
 type ProductStatsResponse struct {
 	TotalProducts   int64 `json:"total_products" comment:"产品总数"`