openai/gpt-chat-latest → A (3:2)

Side A adds a substantive new capability by introducing a first-class `room create` CLI command, wiring it through RPC, enforcing bearer authentication, updating documentation, and simplifying the underlying room model by removing the unused visibility concept (`ThreadVisibility`, room state, and RPC parameter) in favor of a simpler room registry. Side B delivers a polished UI feature—a garden ranking copy button with markdown generation, POST `/ui` handling, and browser/tests—but it is primarily a convenience feature rather than a foundational project capability.