Cryptographic identity (DNI)
Each soul carries a SOUL-issued, Ed25519-signed identity credential. Without a valid DNI, Core and Platform fail closed — the brain won't start and memory won't load. It is verified offline and revalidated with SOUL at least every 30 days, and it survives model changes: the model is borrowed, the identity is yours. Fail-closed against impostors, never against the owner — a lapsed credential locks access, it never deletes the soul.