Function new_v5 

pub fn new_v5(namespace: &Uuid, name: &[u8]) -> Uuid

Mint a name-based (UUIDv5, SHA-1) identifier under namespace. The same (namespace, name) always yields the same UUID, so it content-addresses a derived fact: re-running a query re-derives the identical child_uuid, letting lineage rows dedup/accumulate idempotently rather than growing unboundedly. (#604)