Adjacent secret leak in show_cmd noticed during Task 3 code review.
SecurityConfig has two sensitive fields and the redaction block only
covered pin_hash. vigilar config show would print the recovery
passphrase hash verbatim whenever one was configured.
One-line fix; same redaction pattern as the surrounding secrets.
Part of issue #2.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2032fac227