openai/gpt-chat-latest → B (4:1)

Side B adds substantial new infrastructure with a persistent JSONL event log (append/load, directory creation, error handling), a durable view-count store with background flushing, and deployment/build configuration via Dockerfile and Fly.io files. Side A makes a targeted behavioral fix by changing sibling navigation so each unranked sibling is its own group and adds a regression test, which is valuable but much narrower in long-term impact than the foundational runtime and deployment capabilities introduced in Side B.