The 'rejects worksheets that exceed the row limit' test took 6599ms on
the QNAP act_runner, overflowing the default 5000ms vitest timeout.
Writing and parsing MAX_DISPO_WORKBOOK_ROWS+1 rows via ExcelJS is slow
on constrained hardware. Extend timeout for all three writeWorkbook-
dependent tests (row limit, column limit) to 30s, matching the fix
already applied to excel.test.ts and workbook-export.test.ts.