The round-3 reconciliation took main's ChatHeader wholesale and wired its
full prop set, resurrecting the scripts/open-in/git-actions cluster the
branch had deliberately relocated into the thread panel. Restore the
79-line slim header (project favicon + name + thread title) and its
minimal ChatView call. #5592's header actions stay a documented v2
follow-up, as decided in round 2.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>