feat(backend): 出入库搜索重构 + 商品编码搜索 + KPI/确认售价/详细搜索

- 搜索 keyword 命中改为 单号/酒名(名+拼音)/商品编码，去掉往来单位匹配
- applyStockOrderDetailFilters 合并明细过滤为单条子查询（同一明细语义）+ 新增 product_code
- 新增出入库 KPI summary、出库确认售价(confirm-sale) 及路由
- 补充/更新对应单元测试

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/router/router.go

@@ -147,6 +147,7 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 		stockIn := api.Group("/stock-in")
 		{
 			stockIn.GET("/orders", stockInH.List)
+			stockIn.GET("/summary", stockInH.Summary)
 			stockIn.GET("/orders/:id", stockInH.Get)
 			stockIn.POST("/orders", stockInH.Create)
 			stockIn.PUT("/orders/:id", stockInH.Update)
@@ -166,6 +167,7 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 		stockOut := api.Group("/stock-out")
 		{
 			stockOut.GET("/orders", stockOutH.List)
+			stockOut.GET("/summary", stockOutH.Summary)
 			stockOut.GET("/orders/:id", stockOutH.Get)
 			stockOut.POST("/orders", stockOutH.Create)
 			stockOut.PUT("/orders/:id", stockOutH.Update)
@@ -177,6 +179,8 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 			stockOut.PUT("/orders/:id/withdraw", stockOutH.Withdraw)
 			// 退单（已审核单退货，库存加回+冲应收）：管理员/超管 或 本人（service 内判权）
 			stockOut.POST("/orders/:id/return", stockOutH.Return)
+			// 确认售价（先出后定价，重算应收）：仅管理员/超管（service 内判权）
+			stockOut.POST("/orders/:id/confirm-sale", stockOutH.ConfirmSale)
 		}
 
 		// 库存