Share cards that render themselves — LearnStart's OG set, built from the site's own components

LearnStart had no og:image at all: every link anyone shared unfurled as a bare grey box. It now ships four share cards across banner, WhatsApp-tall, portrait, and square — and none of them are drawn by an image library. The card is a real Astro page built from the real FlameMark and the real theme tokens, photographed by headless Chrome. Change a gradient token and the share card changes with it.