There are two cases where the draft auto-save might fail because the
user is no longer authenticated:
- The user signed-out in another tab,
- The brower quit and re-opened, so the Session cookie expired.
In both cases, the auto-save will never succeed until the user
authenticates again, so displaying a "Retry" button is cruel.
Moreover, in plus of all auto-save requests failing with a small error,
the actual hard failure only occurs after filling all the form and
trying to submit it. Then the user is redirected to the sign-in page –
but all their changes are lost.
Instead, we now redirect to the sign-in page on the first 401 error
during the auto-save, let the user sign-in, and then redirect back to
the form.
