Enter human adjudication as a root-owned episode atomically

When fresh assisted evidence requires human adjudication, atomically create a versioned episode on the canonical visible root. Automated recomputation, completion holds, child derivation, and later workflow advancement must preserve an unresolved episode. Decisions are scoped to that episode, so legacy review history cannot authorize a later review. A machine-generated review status without an episode may remain recomputable; distinguish an automated proposal from a human-owned adjudication lock.