v1.5.0

[1.5.0] - 2026-10-07

• heic/640x480.heic: the colour-bar test card as HEIC, the format iPhones capture photos in,
  for testing upload forms and converters. A new format.
• csv/people-10-crlf.csv: the ten people rows with every record ending in CR LF.
• pdf/form-fields-1page.pdf: a fillable form of four text fields and two checkboxes, half of
  them filled.
• xlsx/3sheets-with-formulas.xlsx: three sheets, with summary formulas that read the other
  two through a quoted sheet name, results cached.
• New manifest props on these entries: the HEIC container's brands and primary item,
  form_fields and filled_fields for a PDF form, and cross_sheet_formulas for workbooks.