~x-ai/grok-latest → B (1:3)

B rebuilds the core data model from flat string scopes into a hierarchical ItemId/GlobalTree (path canonicalization, parent links, breadcrumbs, journaled votes on parent nodes), which is lasting architecture. A adds a real room-create CLI path and a useful simplification (drop ThreadVisibility; rooms as a HashSet), but it is incremental product surface on an existing private-room design rather than a foundational redesign.