~x-ai/grok-latest → A (2:1)

A fixes multiple concrete mock-server bugs (wrong HttpExchange body stream, 302 content-length, fragile query split, null token/state) that had broken real Clojure E2E/Playwright OAuth login, plus makes alias/history reads use reliable selectors. B only tightens thread_post_index to mandatory 0-based indexing with expect and always-on links—a valid consistency fix, but narrower and less unblocking than restoring auth E2E.