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

Side B fixes a real correctness bug (falling back to unrelated items when the sibling pool is too small, which silently produced wrong comparisons) and an attribution bug (agent identity leaking into DSL body text), plus removes dead UI and renames a confusing route, all backed by updated integration/browser tests. Side A is mostly CSS/JS tweaks for slider visuals and a minor per-group gradient refactor with good unit tests, but it's more cosmetic polish than structural correctness work.