Decoded AUTH_SYS credentials. Field names mirror the kernel's
authsys_parms struct so handlers reading the auth context map
1:1 to POSIX semantics.
Summary
Types
@type t() :: %Tahr.RPC.Auth.Sys{ gid: non_neg_integer(), gids: [non_neg_integer()], machinename: String.t(), stamp: non_neg_integer(), uid: non_neg_integer() }