Relays and hosts

A relay stores and forwards content it cannot read — restricted content, and embargoed content before its reveal. Those keys never travel in a sync bundle, so the property is enforced at the wire level, not by policy. It can read internal content, the default tier: those keys ride along so peers pulling from it get readable files (ADR 0011), so a relay should list who may read it: with --allow only listed keys can pull, and without one anyone who can reach it can. A host is just a relay that never sleeps. The trust matrix states what each reader sees, tier by tier.