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

Side B is a real, integrated change: it adds a working CLI `room create` command, simplifies the reducer's room model (removing dead ThreadVisibility complexity), updates RPC, events, docs, and multiple test suites consistently across the codebase. Side A adds a useful but purely additive dev-only tool (sorterc) that doesn't touch or improve existing production code paths, making its value more isolated and lower-stakes compared to B's cross-cutting simplification and feature completion.