`set_info` changed only `/Info`. Files that carry XMP (LibreOffice and Word
exports, PDF/A) kept the old dc:title and dc:creator, so viewers that read
XMP first kept showing the old title, and PDF/A preflight reported the two
as different (6.6.3).
The matching XMP property (Title dc:title, Author dc:creator, Subject
dc:description, Keywords pdf:Keywords, Creator xmp:CreatorTool, Producer
pdf:Producer) is now replaced where it stands, added in a description of
its own, or removed with an empty value. The packet is edited as text and
the rest of it stays byte for byte; files without XMP get none, and a
packet that isn't UTF-8 is left as it was.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
9324afaa4f