Pre-push surfaced fmt + clippy (-D warnings) failures in the new code: - rustfmt the 6 new/changed atlas files + the bench example. - features.rs: HashMap → BTreeMap (project bans HashMap for determinism via clippy disallowed_types; the bucket map is lookup-only either way). - attractor_matching.rs: drop now-redundant .clone() on AttractorType (it became Copy in #953) — clippy clone_on_copy. - drainage.rs tests: manual range → (1..=12).contains(&n). - features.rs test: drop .clone() on Copy AttractorType. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>