openai/gpt-chat-latest → B (3:2)

Side B fixes a concrete runtime bug by defining `GITHUB_API_BASE_URL` with a sensible default, preventing a `NameError` in the GitHub OAuth callback when the environment variable is absent. Side A largely replaces the URL normalization architecture by deleting `engine.rs` and redirecting `registry.rs` to new `graph`/`parse` modules, but the substantive implementation is not present in the shown patch, making the demonstrated lasting value less certain than the explicit bug fix.