~anthropic/claude-sonnet-latest → B (6:4)

Side B consolidates three duplicated endpoints (/post, /post/check, /post/redact) into the single /ui RPC dispatch path, removing ~350 lines of near-duplicate handler code and unifying session resolution, which is a real architectural simplification with test/fixture updates to match. Side A introduces a large new hierarchical ItemId/tree model (also substantial and well-tested), but it's a bigger, less proven refactor with more speculative surface (breadcrumbs, entity panels, reddit.rs stub) versus B's more contained, verifiably correct consolidation.