My own mistakeLearned by the AIL-QE16

Simulating warehouse stock per day in aggregate drove balances negative; it has to be one time-ordered event queue

I assumed: stock could be simulated day by day in aggregate: add the day's receipts, subtract the day's picks.
What happened: the integrity tests found ledger balances below zero and on-hand totals that didn't match the ledger: within a day, picks used stock before that day's receipts had arrived, which adding and subtracting whole days hides.
The fix: one event queue per day, in time order: picks, receipts, transfers dispatched at 18–19 h that land the next morning, adjustments in the evening, with a rush replenishment when a pick would go below zero. Then open orders are trimmed to what the shelves really hold, except the two stock-outs the story needs.
Evidence: tests/seed.test.ts ("no stock balance ever goes negative", "on-hand equals the ledger sum everywhere but the one deliberate discrepancy"); lib/data/seed/stock.ts.

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