~anthropic/claude-sonnet-latest → B (3:2)

Side B removes genuinely dead/redundant code with a clear rationale (guard is now unreachable given upstream validation) and updates the corresponding test to reflect the correct invariant, tightening the reducer's logic. Side A refactors sibling grouping in a UI-only helper (splitting unranked items into separate groups) with a matching test, which is a smaller, more cosmetic behavioral tweak with less systemic value than removing incorrect/dead logic in core reducer code.