//! The design-library protocol's client side: a one-shot request plus a held session
//! ([`client`]), the local-vs-remote source abstraction the viewer's library UI reads
//! through ([`source`]), and the pull-mirror sync that copies a remote worker's
//! library into the local database ([`mirror`]). `mirror` and `source` both build on
//! `client`'s connection handling rather than duplicating it.