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

Side A fixes an actual UI/logic bug in sibling navigation grouping (each unranked sibling now gets its own group instead of being lumped together), with an updated doc comment and a targeted regression test verifying the new behavior. Side B only adds a randomized statistical test for existing rank centrality logic without changing any production code, providing validation but no functional improvement or bugfix.