Ensure forecast snapshot date exists

db/migrations/0016_stock_lot_forecast_history.sql

@@ -1,6 +1,7 @@
 BEGIN;
 
 ALTER TABLE stock_lot
+  ADD COLUMN IF NOT EXISTS sellout_date DATE,
   ADD COLUMN IF NOT EXISTS sellout_forecast_status TEXT NOT NULL DEFAULT 'no_demand',
   ADD COLUMN IF NOT EXISTS sellout_forecast_confidence TEXT NOT NULL DEFAULT 'none',
   ADD COLUMN IF NOT EXISTS sellout_forecast_daily_demand NUMERIC(14, 6) NOT NULL DEFAULT 0,