Purchase Orders: Expected Complete Date In Details, Filterable By Range

The purchase order details card now shows and edits Expected Complete Date — the date you expect the PO to be fully complete — wired to the existing field that the CSV importer already populates. The purchase orders list and the export also gain the matching date-range filter for Expected Complete Date, so reports can be sliced by it the same way as the other PO date fields.

This consolidates around the existing Expected Complete Date instead of the briefly-shipped Ready Date field; per product direction, Ready Date is no longer surfaced in the UI.