~x-ai/grok-latest → A (2:1)

A ships a full invite path (mint RPC, /join redemption wired through OAuth, multi-cap RoomGrant, RoomAudit, CLI, and invites.bb) plus thread timeline/system rows—real product surface with end-to-end tests. B improves identity design (UUID-canonical multi-provider link/conflict handling, Reddit OAuth, linked-provider privacy, batch trust-weight fix) but largely extends an existing OAuth/session model rather than adding comparable new capability.