Social unfurl cards (Open Graph)

Every page can render a branded 1200×630 Open Graph card — your logo over a diagonal gradient of the theme’s primary color, with the page’s breadcrumb, title and description — which becomes that page’s og:image.

Cards are opt-in: set og: {generate: true} and an absolute baseUrl, since a social scraper needs an absolute URL to fetch. They are pure build output, written fresh under _aardvark/og/ on every vark build and never committed, and vark dev skips them entirely so the editing loop stays fast — which also means an unfurl preview won’t resolve against the dev server. A page can override its card with image: in front matter.