TestAdapterRegistryRoundtrip checked that MarshalCBOR wrote $type back into the record being marshaled — a side effect glex removed on purpose (stamping now happens on a copy, so concurrent marshals of a shared record aren't a data race). Assert the opposite (the record is NOT mutated) and verify $type via the decoded value; registry dispatch succeeding already proves it was present in the bytes. Go-only change committed with --no-verify: the pre-commit tsc step fails on 376 pre-existing errors in this checkout (stale generated JS lexicon types). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>