openai/gpt-chat-latest → A (5:1)

Side A fixes multiple concrete failures in the OAuth test infrastructure: it corrects query parsing (`str/split` with regex), reads POST bodies from `getRequestBody`, avoids null crashes when parsing bearer tokens and missing state, fixes redirect response handling, wraps handlers with error reporting, and updates Playwright helpers to use selectors reliably. Side B mainly changes rank-history indexing semantics by replacing a fallback with `expect`, updating documentation/tests, and always rendering a link, which is a narrower behavioral cleanup with less broad impact than restoring broken end-to-end authentication flows.