ai-bookkeeper refused the Order History report that Amazon Business exports ("No transaction lines were found"). Its columns are Order Date, Title and Item Total, none of which the bank reader knew. Found by running the 19 statement fixtures of the open-source ledger-autosync project through the reader; every other file read.
Those three headers are now aliases for date, description and amount. The report lists purchases only, so every amount is positive; the reader's existing all-positive warning fires and --invert books them as charges. Two tests with made-up rows cover both. Not yet checked against a real report with refunds or multi-currency orders. Estimates only, not accounting advice.