openai/gpt-chat-latest → A (3:2)

Side A closes several authentication and security gaps by making vote actor resolution fail-closed instead of silently falling back to anonymous users, adding Secure cookie handling based on HTTPS, tightening open-redirect sanitization, gating mock OAuth behind an environment flag, and pinning the git dependency by revision for reproducible builds. Side B fixes an important XSS risk by sanitizing untrusted Reddit HTML with ammonia before rendering, but it is a more narrowly scoped security improvement compared with A's broader, durable authentication and deployment hardening.