1step,rule,n_before,n_after,n_removed,rationale21,drop months before 1992-03-01 (lags ip_growth_{s-2} and neworder_chg undefined/not in spec),417,415,2,TASK.md training window starts at s=1992-03-0132,keep feature months s with s+1 <= last origin 2026-08-01 (s <= 2026-07-01),415,413,2,target y_{s+1} must be dated <= origin; later months unavailable4