Add the TOTP enroll/confirm/disable surface and Argon2id-hashed recovery
codes as the v1.23 second factor.
- totp.ts wraps otpauth (zero-dep) pinned to the interop floor (SHA-1, 6
digits, 30 s) with a +/-1 drift window. Replay protection persists the last
accepted time-step per account (User.totpLastStep, migration
0202_v123_totp_laststep) and rejects any step that is not strictly newer,
so a captured code dies the instant it is accepted once.
- recovery-codes.ts issues ten single-use, high-entropy codes, Argon2id-
hashed at rest, shown once; regeneration replaces the entire prior set in a
transaction and verification burns the matched code with a guarded update.
- The TOTP secret is stored AES-256-GCM encrypted (already registered in the
encrypted-columns registry + rotation script); decrypt is fail-closed.
- Routes: setup (pending secret), confirm (activate + issue recovery codes),
disable (step-up + current factor), recovery-codes/regenerate (step-up).
Setup/confirm are cookie-only; disable/regenerate add requireFreshMfa.
- scripts/disable-mfa.ts is the operator escape hatch for a locked-out
self-hoster, audited, run via pnpm dlx tsx.
