first bytes: EF BB BF (UTF-8 BOM so Excel reads UTF-8)
rows written: 3
  Order id,Order date,Region,Product,Qty,Unit price,Amount,Status,Note
  1,2025-05-30,Chennai,Product-384,20,464.83,9296.60,RETURNED,INV/2025-26/0000001 dispatched via hub 71
  2,2025-07-29,Pune,Product-121,20,596.20,11924.00,RETURNED,INV/2025-26/0000002 dispatched via hub 46
  3,2025-11-22,Kolkata,Product-6,11,61.05,671.55,SHIPPED,INV/2025-26/0000003 dispatched via hub 51

comma, quote and newline inside fields: "Pune, MH","said ""hi""","line1\nline2"\n

  =HYPERLINK("http://x","pay")     -> '=HYPERLINK("http://x","pay")
  +91 98200 00000                  -> '+91 98200 00000
  -2+3                             -> '-2+3
  @SUM(A1)                         -> '@SUM(A1)
  Mumbai                           -> Mumbai

raw CSVWriter into a broken stream: writeNext called 10,000 times, none threw
  checkError() = true, getException() = java.io.IOException: Broken pipe
CsvExporter into the same stream: IOException: CSV write failed (cause: java.io.IOException: Broken pipe)