fix(admin): 修正仓库产品总价计算逻辑

- 将总价计算逻辑中的 $res['price'] 修改为 $res['purchase']
- 此修改确保了使用正确的购买价格来计算总价

app/admin/logic/warehouse_product/WarehouseProductLogic.php

@@ -320,7 +320,7 @@ class WarehouseProductLogic extends BaseLogic
                 }
                 $datas = [
                     'nums' => $params['nums'],
-                    'total_price' => bcmul($params['nums'], $res['price'], 2),
+                    'total_price' => bcmul($params['nums'], $res['purchase'], 2),
                 ];
                 $res->save($datas);
                 $finds = WarehouseProduct::where('oid', $res['oid'])->field('sum(nums) as nums')->find();