The front page's featured repository draws §5's card, and no front-featured class remains in src/web/studio/home.ts #4690

Done:

• [ ] featuredCard() in src/web/studio/home.ts draws §5's card() (picture as the card's look, title and description in the body), matching the app tiles below it.
• [ ] grep front-featured src/web finds only src/web/style/.
• [ ] test/front.test.ts finds the featured repository's card by its aria-label and link instead of class="front-featured".

Markup only: the stylesheet and docs/DESIGN.md are not touched in this pull (their rules leave in a follow-up), so it cannot conflict with the many pulls editing src/web/style/content.ts. Replaces half of #4596, whose tries went red on the Files-page timing test (planned separately). Run bun x tsc --noEmit, bun scripts/design-lint.ts and bun test test/design-lint.test.ts before pushing; where counts fall, lower docs/design/baseline.json in the same pull.