openai/gpt-chat-latest → B (3:5)

Side B introduces a substantial new offline tooling capability by factoring reusable server logic into an `offline` module, adding `compile_document`, JSONL replay/loading, diagnostics (`scan_jsonl`), a dedicated `sorterc` workspace binary, and unit tests. Side A adds a useful `RoomList` RPC, CLI subcommand, response type, and integration tests for per-user room visibility, but its scope is narrower than the reusable developer tooling and validation infrastructure added in Side B.