Add `card` component (React + Angular)

[sjoerdbeentjes]

Part of #43.

React (@surfnet/react)

• Vendored @shadcn/card — Card, CardHeader, CardTitle, CardDescription, CardAction, CardContent, CardFooter
• cardContract added to @surfnet/contracts (description-only)
• Storybook story with Default, Small, WithHeaderAction, ContentOnly

Angular (@surfnet/angular)

• Vendor Spartan card via CLI
• Wire to cardContract
• Storybook story matching React coverage