Fictional editorial exercise. Keep answer files separate from inputs. A download does not establish a successful task.

Choose UTF-8 and semicolon, keep First row is header: preview 4 rows including the header and 4 columns. Keep columns1/2 as Text; choose Number for3 and Date for4. Export XLSX. Check all 3 IDs as exact text, Amount12.5/0/blank and the3 dates. Zoë checks UTF-8 decoding. Setting column1 to Number must block the17-digit ID; restore Text. bad-date.csv must fail date validation; confirm the source before correcting it. The reference workbook is a typed answer, not a captured native Excel session or a byte-identical tool output.
