openai/gpt-chat-latest → A (4:1)

Side A adds a new user-facing capability by exposing graph connectivity statistics in CLI pair output, including density, component count, connection status, and dedicated tests covering connected and disconnected cases. Side B mainly tightens an invariant by replacing fallback values with `expect`, aligns documentation and UI around 0-based thread indices, and adds assertions, but it is largely a consistency/refinement change rather than a substantial new feature.