Overrides res.users._login. When the login string does not resolve to
any user, super() raises AccessDenied; we record a row with user_id=NULL
and failure_reason="unknown_user", then re-raise. Closes the gap where
typo'd or scanned logins would otherwise vanish from the audit trail.
The existing _fc_record_login_event helper writes through an independent
registry.cursor(), so the audit row survives the rollback that follows
the re-raised AccessDenied.
Note: in Odoo 19 _login is a plain instance method (not the classmethod
it was in earlier versions) and takes (credential, user_agent_env). The
original plan was written for the classmethod signature; corrected here
and recorded in CLAUDE.md rule #10 so future-Claude does not waste time
re-discovering it.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>