/**
 * Assign rows to a table source, adding vt_id only when missing (avoids full-row copies).
 */
export function assignTableRows(
  rows: Record<string, unknown>[]
): Record<string, unknown>[] {
  return rows.map((row, index) => {
    if (row.vt_id !== undefined && row.vt_id !== null) {
      return row;
    }
    return {
      ...row,
      vt_id: row.id ?? index,
    };
  });
}