Design carrier adapter interface

[mastertape]

Design a carrier adapter interface that maps external carrier workflows to internal opening-right lifecycle events.

Acceptance criteria:

• Adapter boundaries are documented.
• Core OpenParcelBox works without any carrier adapter installed.
• The interface supports one-time and time-limited rights.
• The interface does not require a remote open-door command.
• Unsupported carriers can be represented as manual/local-code workflows.

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