mintNewEntities

whether a mention the resolver could NOT match to an existing entity may be persisted as a NEW entity node. Default FALSE: unresolved mentions stay unresolved (the proposition is still persisted; its mention simply carries no resolvedId), so extraction never creates phantom "mentioned in proposition" nodes for things the graph doesn't know — a term the user merely asked about must not become an entity. Opt in per ingestion for sources whose mentions deserve nodes.