openai/gpt-chat-latest → A (4:1)

Side A adds a substantial new offline development capability: a workspace tool (`sorterc`) with compile and JSONL scan commands, reusable server-side offline APIs (`offline.rs`), tests, and documentation, enabling validation, replay, and diagnostics without a running server. Side B usefully exposes room creation in the CLI and simplifies the room model by removing unused visibility state, but much of the patch is API cleanup and documentation updates rather than adding comparable long-term functionality.