aa480f7ca3
E1: bound incoming payload length to 64 KiB at both vec![0u8; len] sites (request_recovery + test daemon) so a buggy or malicious child cannot trigger OOM by sending len=0xFFFFFFFF. E2: decode all 6 RecoveryAction discriminants in DriverErrorResponse::decode (previously 4/5 silently dropped to None). Extend encode_decode_response_round_trip to cover CanRecover and Recovered.