Gitea/Forgejo has no repo-scoped /issues/search path — every dedup
search 404'd on a real forge, so everything spooled and nothing ever
filed. Dedup now queries GET /issues?state=open&type=issues&q=<marker>
(paginated, server-side q) with a client-side marker contains-check on
title/body. FakeForge keeps mirroring the server contract (q matches
titles only) instead of the client's filter; docs updated.