优化仓库商品逻辑，支持商品未存在时的处理

- 当仓库商品不存在时，自动创建商品库存记录，而不是抛出异常
- 新增商品库存时，'nums'字段设置为负数，以表示缺货数量
- 保留了仓库ID和产品ID的关联，便于后续处理

app/admin/logic/warehouse_product/WarehouseProductLogic.php

@@ -130,7 +130,13 @@ class WarehouseProductLogic extends BaseLogic
                     $total_price = bcmul($after_nums, $params['purchase'], 2);
                     WarehouseProductStorege::update(['nums' => bcsub($storege['nums'], $params['nums']), 'total_price' => $total_price], ['id' => $storege['id']]);
                 } else {
-                    throw new BusinessException('仓库商品不存在' . '|' . $params['product_id']);
+                    $data = [
+                        'warehouse_id' => $params['warehouse_id'],
+                        'product_id' => $params['product_id'],
+                        'nums' => -$params['nums'],
+                        'total_price' => 0
+                    ];
+                    $storege = WarehouseProductStorege::create($data);
                 }
             } else {
                 $storege['nums'] = 0;