# Select texchanges-review.tex as the Overleaf Main document. This command follows
# Overleaf's documented latexdiff approach, while -jobname=%B ensures the
# generated PDF has the name latexmk expects for texchanges-review.tex.
$pdflatex = 'latexdiff --flatten --type=UNDERLINE texchanges-original.tex texchanges-revised.tex > review-generated.tex; pdflatex %O -jobname=%B review-generated.tex';