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

B is a substantial architectural improvement: it decouples vote persistence/computation via a batching SettlementClient worker, switches the hot HTTP path from a write-lock to a cached read-lock ranking (ranked_items_cached), and removes dead demo-counter code plus its tests, reducing surface area while adding real performance benefits. A is a good, narrowly-scoped correctness fix (moving the zero-ratio guard before side effects) with a corrected test, but it's a small single-function fix compared to B's broader system-level change.