openai/gpt-chat-latest → A (3:2)

Side A refactors the parser graph to be immutable after construction, removes unnecessary Rc<RefCell> indirection, makes handlers Send + Sync, and caches the graph in a OnceLock so it is built once and safely reused. Side B adds a substantial account-management UI (alias switching, claiming, OAuth relinking, styling, and page restructuring), but it is primarily a feature/UI expansion rather than a foundational runtime improvement with broad, lasting performance and thread-safety benefits.