style：产品BOM-产品BOM明细-单位自动带入

src/views/mes/bom/components/BomDetailForm.vue

@@ -17,6 +17,7 @@
               clearable
               filterable
               :placeholder="t('FactoryModeling.ProductBOM.detailMaterialPlaceholder')"
+              @change="(val) => handleProductChange(val, row)"
             >
               <el-option
                 v-for="item in productList"
@@ -138,6 +139,16 @@ watch(
   
 )
 
+/** 原料选择变更时，自动带入单位 */
+const handleProductChange = (productId: number | undefined, row: any) => {
+  if (productId) {
+    const product = productList.value.find((item) => item.id === productId)
+    row.unitId = product?.unitId ?? undefined
+  } else {
+    row.unitId = undefined
+  }
+}
+
 /** 新增按钮操作 */
 const handleAdd = () => {
   const row = {