openai/gpt-chat-latest → A (5:2)

Side A introduces a substantive shift from flat string scopes to a canonical hierarchical `ItemId`/`GlobalTree` model, updates vote recording and replay to use that structure, adds path normalization, breadcrumbs, node persistence, and adapts the UI and parser around the new design. Side B mainly reconnects and expands the web UI (cookie-based browser sessions, room routes, posting forms, and routing), which is useful, but it is largely wiring on top of existing capabilities rather than introducing a comparably foundational data model and persistence change.