Where the console and the portal share a host (shared/fallback mode —
this VM's own mode), both guards keep their login key in the SAME
session. session()->invalidate() is flush() + migrate(true) — it
discards every attribute in the session, not only the operator's, so
signing out of the console silently signed a customer out of the
portal too if the same browser carried both. Replaced with
session()->regenerate(): a new session id, so there is no fixation
risk, while attributes belonging to any other guard survive untouched.