~anthropic/claude-sonnet-latest → B (80:20)

Side B is a real, working feature: it vendors a durable RocksDB crate, moves entity JSON out of the in-memory tree into on-disk storage, switches event-log loading to a streaming replay API, and updates reducer/state/reddit modules plus tests to match, directly cutting startup RAM and adding persistence infrastructure. Side A is only a planning document (plan.md) plus a thin, largely unused RouteContext wrapper that still delegates to the old ThreadNav/CanonicalItemUrl string logic, contributing no functional change or bugfix to the codebase.