~x-ai/grok-latest → B (2:1)

Side B permanently wires multi-room UI (ThreadNav abstraction, /r/* routes with ACL checks, compose/post forms via rpc_post_with_bearer, cookie sessions + login/logout) turning public-only threads into a functional web product; Side A mainly refactors one Reddit fetch path to SSE (new fetch/ mod, oneshot results, JS consumer) which improves polish but is narrower and more internal.