~anthropic/claude-sonnet-latest → B (9:1)

Side B fixes an actual algorithmic bug (bipartite/oscillating Markov chain in the ranking power-iteration) with a correct, well-justified change grounded in the cited paper, plus regression tests in both Rust and Clojure across multiple topologies. Side A is purely a planning document and a thin wrapper struct (RouteContext) that just delegates to existing ThreadNav methods without migrating any call sites, providing no functional change or real refactor yet—its value is aspirational/documentation only.