openai/gpt-chat-latest → A (3:2)

Side A closes a significant security gap by sanitizing untrusted Reddit `body_html` with `ammonia` before passing it to `maud::PreEscaped`, adds a dedicated sanitizer module, and includes tests verifying scripts and event handlers are stripped while benign markup is preserved. Side B fixes an important browser-auth design bug by removing shared sentinel delegates, switching browser sessions to `None` delegates, and adding strong integration tests for multi-user voting, but its impact is narrower than preventing XSS in rendered content.