openai/gpt-5.3-chat → A (5:1)

Side A introduces a substantial cross-cutting feature set: a full theme system with cookie persistence, request/response propagation, layout changes, new endpoints, and consistent integration across many HTML views and auth flows. It also adds room-aware URL handling throughout the RPC layer, affecting core API behavior. Side B is more incremental—UI/UX improvements (vote counts, HUD unpin behavior), small helper logic, and tests. While useful, it’s localized compared to A’s broad architectural impact.