If you are not using the HTML5 pushState history API or not using client-side routing at all, it is unnecessary to specify the URL from which your app will be served. Instead, you can put this in your package.json:"homepage": ".",...
"History" is in date order, so adding new entries from "Orders" should be easy, just by adding rows to the bottom. Updating existing rows will be harder, because I want it to update if the row has changed but not be deleted or changed when the "Orders" sheet...