Lay the account-security and data-sovereignty substrate for v1.23. No
user-facing behaviour yet — schema, crypto registry, redaction, and the
note-encryption data path only.
Schema + migrations:
- 0199 — User totp_secret_encrypted / totp_confirmed_at / mfa_enforced /
passkey_upgrade_nudge_dismissed; Session mfa_verified_at / last_active_at;
Passkey last_used_at. All additive, nullable / defaulted.
- 0200 — mfa_challenges (single-use step-up ticket; only the ticket hash is
stored, so no session or token is ever minted before the second factor),
mfa_recovery_codes (Argon2id at rest), webauthn_mfa_credentials (second-factor
keys, kept separate from passkeys, which remain the passwordless-primary set).
- 0201 — mood_entries.note_encrypted + measurements.notes_encrypted (BYTEA),
matching the existing free-text encrypted-note convention.
Free-text health notes:
- New writes encrypt the mood / measurement note into the *_encrypted column and
null the legacy plaintext column; reads prefer the ciphertext and fall back to
plaintext only for not-yet-migrated rows, via a single read/write helper.
- A boot-time job migrates existing plaintext rows in an idempotent,
transactional, fail-closed pass (encrypt, then null the plaintext, per row in
one transaction; safe to re-run; a row with content is never left both-null).
- The legacy plaintext columns are kept this release and dropped in a follow-up
once the backfill reports zero remaining rows — the same boundary the
key-rotation playbook uses before dropping a legacy key.
Crypto coverage:
- Register the three new encrypted columns and wire them into the key-rotation
script so a rotation never orphans them.
- Extend the observability and log redaction denylists so TOTP secrets, MFA /
recovery / backup codes, and export passphrases never reach a wide event.
