PARTIALLY_CLOSED was missing from the open-filter so affected POs
disappeared from the submitter''s My Orders view entirely, making it
impossible to confirm remaining deliveries.
Also hardens confirmReceipt() against negative delivery quantities
and extends partial-receipt.spec.ts with US-8c/8d/8e covering the
full PARTIALLY_CLOSED revisit flow.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
