DejaVu Sans TTF files required for invoice PDF export.

They are copied here automatically by:
  - composer install / update (post-install script)
  - npm run build (release packaging)
  - php scripts/sync-pdf-fonts.php

Required files (see scripts/required-pdf-fonts.txt):
  DejaVuSans.ttf, DejaVuSans-Bold.ttf, DejaVuSans-Oblique.ttf, DejaVuSans-BoldOblique.ttf

Do not delete this folder from release builds.
