openai/gpt-chat-latest → A (4:1)

Side A introduces a substantial new UI action architecture: a unified POST /ui endpoint with typed HtmlUiAction parsing, JSON form-template substitution, reusable web-post handlers, and integration for expanding thread forms while preserving permission checks. Side B mainly removes a complex autocomplete system in favor of a simpler paste-and-go URL parser and redirect, which simplifies behavior but also deletes large amounts of functionality rather than adding broadly reusable infrastructure.