~anthropic/claude-sonnet-latest → B (6:4)

Side B implements a full end-to-end feature: a new CLI `room create` command, RPC/reducer/event plumbing, simplification of the room model (dropping unused visibility since only private rooms are ever created), plus updated docs/tests across CLI, server, and integration suites. Side A is a smaller, well-tested UI fix (rank color gradient) that improves visual correctness but has narrower scope and impact than B's cross-cutting feature and API simplification.