{
  "synthetic": true,
  "grain": "One unique bank transaction; July and August 2026; USD; no transfers or refunds in this fixture.",
  "columns": {
    "transaction_id": "Unique text key",
    "date": "ISO posting date",
    "description": "Synthetic counterparty",
    "category": "Reviewed classification",
    "amount": "Signed USD: receipts positive, payments negative",
    "ledger_amount": "Signed USD in independently maintained ledger; bank fees intentionally missing",
    "invoice_total": "Absolute USD source-document control amount; not a second cash amount",
    "source_month": "YYYY-MM source-file identifier"
  }
}