~x-ai/grok-latest → B (2:3)

B centralizes brittle, duplicated hostname/redirect logic into util/get-base-url (HOSTNAME-aware) across oauth/login/spotify/twitter/youtube/linear and the frontend origin, plus wires staging deploys—lasting production design. A is real, precise mock/E2E fixes (regex split, getRequestBody, nil-safe tokens/state, handler try/catch) but remains test-only scaffolding.