Replace the random-number stub at dbus.rs:132 with state.issue_recovery,
add ListRecoveryCodes (returns Vec<RecoveryCodeSummary>) and RevokeRecoveryCode.
New polkit actions list-recovery / revoke-recovery (auth_admin_keep). Adds
4 D-Bus integration tests; the previously-stub generate-code test now
exercises the real Argon2id-backed write path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Two-line file format (expires_unix\nargon2id-PHC) keeps the C PAM module
parser trivial — no json-c link needed. Atomic temp+rename means a
concurrent reader never sees a half-written file.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
