-- Two-factor authentication (TOTP) and single-use recovery codes. Applied by store/migrate.rs.
-- totp_secret_sealed holds the instance-key sealed secret (secret::seal output, UTF-8 bytes).
-- totp_enabled stays 0 until the user confirms a code. totp_last_step is the replay guard.

ALTER TABLE users ADD COLUMN totp_secret_sealed BLOB NULL;
ALTER TABLE users ADD COLUMN totp_enabled INTEGER NOT NULL DEFAULT 0;
ALTER TABLE users ADD COLUMN totp_last_step INTEGER NOT NULL DEFAULT 0;

CREATE TABLE recovery_codes (
    id          TEXT PRIMARY KEY,
    user_id     TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    code_hash   TEXT NOT NULL,          -- hex sha256 of the normalized code
    used_at     TEXT NULL
);
CREATE INDEX recovery_codes_user_id ON recovery_codes(user_id);