Signing out when the next registered account had no live client (its
restore failed at boot) fell back to a full logout, but only cleared
the signed-out account's slot and removed just that next account. The
other account's remembered session survived, and on the next visit the
orphan-cookie adoption in `checkAuth` signed the browser back in as
that account and read its password back.
The fallback now drops every remaining account and clears each of
their slots together with the signed-out one. The full logout also
removes the persisted `account-registry` instead of a key that never
existed (`account-storage`).
Linus Rath
8b3e29fe75