A WhatsApp preview card for a static page, without a browser on the server

Our proposals are published as static folders, and pasting one into WhatsApp showed a bare link. WhatsApp does not render SVG, and we did not want a headless browser in the container just to draw a thumbnail. A native rasterizer with its fonts packed inside now writes a 1200×630 PNG on every publish. The pipeline, the two Next.js settings it needs, and what happens when it fails.