extract the purchase order header and the per-style line items from a retail purchase-order detail report. each line item is the main product row (VPN / STYLE / DESCRIPTION / SKU / UPC / pack qty / content / unit qty / unit cost / extended cost); ignore the indented 'PACK TOTAL' sub-rows. description is the product description which may wrap across lines; join into one string. the UNIT QTY column (total units, e.g. 840) is not extracted; take extendedCost as the printed extended cost (unit cost times unit qty). dates are printed as 'MM/DD/YY'; convert to YYYY-MM-DD.
