Built an original, standalone Python

Built an original, standalone Python 3.11 CSV reconciliation sample. It compares two exports by mapped key and reports left-only, right-only, duplicate or blank keys, and field differences. Seven tests and synthetic output demonstrate the behavior; production records can stay on the buyer’s computer. The script uses only the standard library. Explore the public sample: https://github.com/asphyxeth-tech/csv-reconcile-demo