On PO202610005TEL the AI read a 15% discount that was not on the invoice
and cut a line's cost from R146.47 to R124.50. It no longer writes a cost
to order or stock lines. A cost that differs from the invoice's discounted
price shows as a red Price tick, which also keeps the card out of
auto-push, so a person settles it. Earlier cost changes stay visible on
the line. Tests now assert no cost is ever written; runbook and AGENTS.md
updated.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
