fix(订单表单): 将默认税率从0改为13%

src/components/order-form/material-detail-option.js

@@ -354,7 +354,7 @@ export const DEFAULT_FORM_DATA = {
   orderQuantity: 0,
   confirmQuantity: 0,
   unitPrice: 0,
-  taxRate: 0,
+  taxRate: 13,
   taxAmount: 0,
   totalAmount: 0,
   status: MaterialDetailStatus.UNCONFIRMED, // 默认状态：0未确认

src/components/order-form/material-import-dialog.vue

@@ -520,7 +520,7 @@ export default {
             orderQuantity: 1, // 默认订单数量为1
             confirmQuantity: 1,
             unitPrice: 0, // 默认单价为0，2位浮点型
-            taxRate: 0, // 默认税率为0，2位浮点型
+            taxRate: 13, // 默认税率为13%，2位浮点型
             taxAmount: 0, // 默认税额为0，2位小数
             totalAmount: 0, // 默认总金额为0，2位小数
             itemStatus: MaterialDetailStatus.UNCONFIRMED,

src/components/order-form/order-form-mixin.js

@@ -1238,7 +1238,7 @@ export default {
 
           formatted.orderQuantity = quantityValidation.isValid ? Math.round(quantityValidation.value) : 1
           formatted.unitPrice = priceValidation.isValid ? preciseRound(priceValidation.value, 2) : 0
-          formatted.taxRate = rateValidation.isValid ? preciseRound(rateValidation.value, 4) : 0
+          formatted.taxRate = rateValidation.isValid && rateValidation.value > 0 ? preciseRound(rateValidation.value, 4) : 13
           formatted.taxAmount = taxAmountValidation.isValid ? preciseRound(taxAmountValidation.value, 2) : 0
           formatted.totalAmount = amountValidation.isValid ? preciseRound(amountValidation.value, 2) : 0