Remove ENCRYPT/VERIFY from KeyUsage mapping to match Kotlin behavior.
Document BasicConstraints and SKI suppression via rcgen NoCa default.
Fix rotating log off-by-one that kept one extra backup file. Handle
BMPString (UTF-16BE) and VisibleString in X.500 DN parser.
Builds v3 leaf certificate with attestation extension and KeyUsage,
signs with keybox private key via rcgen 0.13.2. Assembles full chain
(leaf + keybox intermediates + root). Supports EC and RSA keybox
signing keys. Uses rcgen's signed_by() with a synthesized issuer
Certificate, no manual DER fallback needed.