Specify opening-right presentation formats

[mastertape]

Specify presentation formats for opening rights, including numeric PIN, QR payload, barcode-compatible payload and signed token.

Acceptance criteria:

• PIN entropy and usability assumptions are documented.
• QR payload alternatives are compared.
• Replay protection and one-time-use behavior are specified.
• Expired, revoked, reused and malformed credentials have defined denial behavior.
• Secret material is never logged in plaintext.

Source: reviewed carrier dynamic access code research in private research inbox.