Function book_from_vta 

pub async fn book_from_vta(client: &VtaClient) -> NameBook

Best-effort book from the two listings that name DIDs on a VTA: the ACL (subject labels) and the contexts (each context’s name, for its own DID).

For surfaces whose own response carries no name — hosted did:webvh records, sealed-bundle banners, mediator tables. Both fetches are swallowed on failure: naming is decoration, and a caller who may read their own DIDs but not the ACL must still get their output.