When the panel runs on a domain+HTTPS and the user has a registered key, the 2FA
challenge offers "Mit Security-Key anmelden" alongside the TOTP/backup-code field.
A verified assertion completes login exactly like a TOTP success; rate-limit +
session gate reused. TOTP and backup codes remain fully usable.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The challenge now falls back to consuming a one-time recovery code when the TOTP
check fails. Relaxed the code input (was numeric, maxlength 6) so a backup code
is typable, and added a hint. Bilingual.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>