openai/gpt-chat-latest → A (9:1)

Side A corrects the rank-history thread index semantics by treating the post lookup as required with `expect(...)` instead of silently defaulting to `0`, updates documentation to distinguish 0-based URL indices from 1-based feed display, always renders the corresponding link, and adds integration tests validating the behavior. Side B only removes an unannotated test function that generated a warning, reducing noise but not changing project behavior.