~x-ai/grok-latest → A (3:1)

A delivers several lasting behavioral fixes: out-of-band delegate attribution, correct early-return when the sibling pool is too small (instead of silently falling back to all items), and removal of a useless swap control, plus the route rename. B only adds a missing GITHUB_API_BASE_URL default—important for avoiding a NameError, but a three-line constant definition with far less ongoing design impact.