F5 (critical, confirmed on the local server): the 2FA step accepts an empty or
missing temp token, so users with 2FA on can be logged into without a password.
F1 confirmed: with the placeholder secret a user's current token can be rebuilt.
F8 confirmed. New findings F6, F7, F9 to F12. Review only, no code changes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>