DeviceRecoveryCodec

Transfer encoding of recovery requests and authorizations, version 1, for applications that move them between devices (QR code, file, their own channel). Not signed as such: the signatures inside cover the statement.

version:u8 = 1 | kind:u8 (1 request, 2 authorization) | statement
| proof of possession (64) | [authorizer signature (64), kind 2 only]

The statement is the one of DeviceRecovery. Decoding is strict (valid UTF-8, exact sizes, no trailing bytes) and throws IllegalArgumentException otherwise. Decoding verifies no signature.