mesh_store_reader held pg_read_all_data, so every caller of mesh-store.query and postgres_query could read every column the store holds: the signing key nodes trust, sealed secrets, password hashes. The reader now holds no role; each minute, on every database, its memberships are revoked and its grants brought to what the consumer's contribution lists under readable, minus any column or table whose name says it holds a secret. Before a statement runs, the reader's own session is asked which secret columns it can read and the statement is refused if any; a statement naming a known secret table is refused before it is sent.