Engine modules: :codec (binary+XML plists), :courier (APNs push client),
:ids (identity lookup), :crypto (the encryption envelope), :registration
(GSA login, albert activation, renewal), :engine (integration + live
drift probes). 344 offline tests; capture-fixture known-answer vectors
for the parsers; live unauthenticated probes validated against Apple.
The bundled FairPlay identity is a synthetic placeholder — Apple-derived
material is user-staged, never shipped. Apache-2.0.