fix: 创建订单时传递length、width、area参数

src/pages/order/create.vue

@@ -394,7 +394,10 @@ export default {
         items: this.orderItems.map(item => ({
           productId: item.productId,
           quantity: item.quantity,
-          price: item.price
+          price: item.price,
+          length: item.length || null,
+          width: item.width || null,
+          area: item.area || null
         })),
         discountRate: 100,  // 保留折扣率逻辑，默认100%
         discountMoney: parseFloat(this.discountMoney) || 0,