~x-ai/grok-latest → A (3:2)

A fixes a real multi-user correctness bug by removing shared browser sentinel delegates (WEB_BROWSER_AGENT/INVITE_BROWSER_AGENT), making PendingSession.agent optional end-to-end, and proving two humans can vote without AgentBound collisions via solid integration tests. B adds substantial Reddit fetch infrastructure (broker, OAuth, rate-limit backoff, JSON mapping), but it is still an incomplete integration surface (plus todo/.gitignore noise) rather than a core multi-user correctness repair.