When the cookies imported but the new profile's settings write failed, the
wizard reported "The browser's cookie database could not be read" — the one
thing that had just succeeded. The failure now carries its own reason,
`profileNotSaved`, with copy that says the cookies came over and the profile
couldn't be kept (its partition is cleared again so nothing is stranded), and
it offers a retry.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>