feat: 添加购买分组功能，替代跨分类购物选项

backend/internal/api/handlers/product.go

@@ -49,17 +49,17 @@ func (h *CategoryHandler) Create(c *gin.Context) {
 	}
 
 	category := models.Category{
-		Name:               req.Name,
-		Description:        req.Description,
-		ParentID:           req.ParentID,
-		MinAmount:          req.MinAmount,
-		MaxAmount:          req.MaxAmount,
-		MinQuantity:        req.MinQuantity,
-		MaxQuantity:        req.MaxQuantity,
-		MinWeight:          req.MinWeight,
-		MaxWeight:          req.MaxWeight,
-		AllowCrossCategory: req.AllowCrossCategory != nil && *req.AllowCrossCategory,
-		SortOrder:          req.SortOrder,
+		Name:             req.Name,
+		Description:      req.Description,
+		ParentID:         req.ParentID,
+		PurchaseGroupID:  req.PurchaseGroupID,
+		MinAmount:        req.MinAmount,
+		MaxAmount:        req.MaxAmount,
+		MinQuantity:      req.MinQuantity,
+		MaxQuantity:      req.MaxQuantity,
+		MinWeight:        req.MinWeight,
+		MaxWeight:        req.MaxWeight,
+		SortOrder:        req.SortOrder,
 	}
 
 	if err := utils.DB.Create(&category).Error; err != nil {
@@ -123,8 +123,8 @@ func (h *CategoryHandler) Update(c *gin.Context) {
 	if req.SortOrder != nil {
 		updates["sort_order"] = *req.SortOrder
 	}
-	if req.AllowCrossCategory != nil {
-		updates["allow_cross_category"] = *req.AllowCrossCategory
+	if req.PurchaseGroupID != nil {
+		updates["purchase_group_id"] = *req.PurchaseGroupID
 	}
 
 	utils.DB.Model(&category).Updates(updates)