openai/gpt-chat-latest → B (50:1)

Side B adds substantial new functionality and architecture: it introduces a unified POST /ui endpoint with typed HtmlUiAction parsing, reusable form-template substitution, shared web-post helper functions, new routing, and UI support for expanding thread forms with permission checks. Side A is a minor cosmetic change that removes the leading separator before the view count (`" · "`), improving presentation but not adding comparable lasting capability.