Mirror jump domain (legacy)
Catalog leftover for short/mirror jump domain (m_j_domain). Not implemented in this build.
Mirror jump domain (legacy)
Catalog label: Mirror/jump domain (m_j_domain). Older docs mentioned an optional domain for short/mirror jump links (empty = current site).
This build has no code that uses m_j_domain and no short-link jump admin UI.
What to use instead
Share normal public file URLs on your site domain. Configure DNS and PUBLIC_APP_URL for the real hostname you serve.
Common problems
Setting a jump domain in search does nothing
Expected stub. There is no separate jump host feature to configure here.