Hello @pczeryba,
Are you looking to use the API or an app to achieve this. If you want to use the API, you can use the duplicate board and specify only the duplicate_board_with_structure argument. You can find that here. If you are looking to use an app, you can use the Duplicates and Uniques app and create a template which will delete your items in your board and set it to run everyday through an integration. Additionally, for your use case, you might want to check out the merge functionality of the Duplicates and Uniques app. It may be great for this particular use case. Hope this helps.