~x-ai/grok-latest → A (3:2)

Commit A lands a core domain redesign: a real ItemId type (Root/Local/Web/Opaque), split wire normalization (item_wire), and end-to-end replacement of CanonicalItemUrl across reducer maps, ranking, RPC, HTML routing, and tests—foundational structure used everywhere items are keyed. Commit B is valuable product/auth work (Reddit OAuth, multi-provider link-to-UUID, private linked-provider UI, pending trust weights in projection batches) but is narrower in blast radius than rewriting item identity through the graph.