Target fields on the admin hints page. The dashboard shows the four
automatic hints after admin hints when their condition is true, using
data Core already serves. HintText renders **bold** and safe links (app
path or https) as React elements, never HTML, in hints and news.
Auto-close without tick hides for this session, X for 7 days, tick + X
for good.
Dashboard dialog shows unseen news entries. Users mark them seen with "Got it"
or revisit via the /whats-new page. Admins publish, edit, and delete entries
on /admin/news. Full i18n support and test coverage included.