xenb-02-dbd26a4: perf(prewarmer): micro-optimize discovery and address review

hold the active capture directly in the storage tree wrapper, removing the per-miss thread-static lookup and the capture counter pool the round/discovered cell sets and the warm-phase cells array; reuse the candidate lists across rounds instead of ConcurrentBag sort discovered cells by address before partitioning so each warm partition resolves the account and storage root once assert the…