fix: cards translation links point to regular PDFs, not nonexistent cards PDFs
The cards template was generating links to {siteName}-{lang}-cards.pdf but translated cards don't exist — only English cards are generated. Changed to link to the regular translation PDFs ({siteName}-{lang}.pdf) which do exist.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>