fix: 统一计划产品计量单位并兼容历史吨单位，避免保存时关联校验失败。

web-admin/src/composables/usePlContractToPlan.ts

@@ -8,6 +8,7 @@ import {
   initLineBrandMetaFromProduct,
   type BrandOption
 } from '@/utils/crm-product-brand'
+import { normalizeProductUnitValue } from '@/utils/crm-product-display'
 
 export interface PlanFormProductRow {
   id?: string
@@ -87,7 +88,7 @@ export function mapContractProductToPlanRow(item: ContractProductForm, index: nu
     brandName: item.brandName || undefined,
     model: item.model || item.productModel,
     categoryName: item.categoryName,
-    unit: item.unit || '吨',
+    unit: normalizeProductUnitValue(item.unit),
     quantity: Number(item.quantity || 0),
     actualQty: 0,
     packageSpec: packageSpecs.length === 1 ? packageSpecs[0] : undefined,