Trailing window backed by SyncRecordStore dedup is strictly better than
a single-day window — a single missed cron run with Last Business Day
loses that day's activity permanently. SyncRecordStore is keyed by
ibkr:trade:<tradeID> / ibkr:cash:<transactionID>, so overlapping pulls
are no-ops.
Caught during the brainstorming review.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
