openai/gpt-chat-latest → A (5:1)

Side A delivers substantial functional infrastructure: it adds browser session-cookie authentication, login/logout flows, web posting that reuses the RPC layer, room-aware forum pages with access checks, new routes, and private-room navigation/composition support. Side B is a focused UI refinement for vote comparison—fullscreen layout, improved edge-history ordering/display, preview morphing after posting, and related CSS/tests—but its scope and long-term architectural impact are much smaller.