~x-ai/grok-latest → A (4:1)

Side A delivers substantial lasting product value by implementing cookie-based web sessions, a full web POST ingest path, ThreadNav abstraction, room/private thread pages with ACL checks, compose forms, and complete routing—making rooms usable in the browser. Side B is a precise and necessary RwLock deadlock fix plus test harness hardening, but narrower in scope than the UI and auth surface A adds.