openai/gpt-5.3-chat → A (3:1)

Side A fixes a functional runtime issue (a NameError in the GitHub OAuth callback) by properly defining and normalizing the API base URL, which directly impacts application correctness. Side B consists mostly of lint cleanups, minor refactors, and test adjustments that improve code quality but do not materially change behavior. Fixing a breaking bug outweighs stylistic and maintenance improvements.