bbe0e3fb21
- Flip cmd_requires_auth() from blacklist to whitelist: only read-only query commands are unauthenticated, all state-modifying commands now require HMAC (VULN-007) - Block AUTH OFF command to prevent remote auth disable; secret rotation still allowed, full reset via FACTORY (VULN-005) - Redact auth secret in boot log to first 4 chars only (VULN-003) - Update HELP text to reflect AUTH change