PrincipalAttested

A seam or connection whose transport accept carries a host-verified Principal. A fabric that can authenticate a connection (e.g. a Ktor server reading call.principal()) attaches one via a withPrincipal wrapper; admission layers read it at admit time and carry it onto the admitted peer.

This replaces out-of-band peer → principal maps: the principal rides the connection object itself, so it cannot desync from the peer it describes.