keep-web supports login flow
Despite being instructed to use the "copy link to clipboard" feature of wb2, users still tend to copy-paste links out of the URL bar to share with others. When these links are opened, the other user is presented with a basic auth username/password dialog. This requires users to provide an Arvados token, but they don't know that.
It would be a better user experience if keep-web redirected unauthenticated users to workbench 2, where they log in (or it loads their existing token) and then redirects back to keep-web with correct credentials.