feat: responsive system, engineering infra, new components, performance

- Section: responsive prop with media query injection
- visual-weights: fontSize clamp() for responsive sizing
- variables.css: add border-radius/shadow/transition/z-index tokens
- ESLint flat config + Prettier + Changeset init
- New components: Footer, NewsSidebar, BreakingNewsBanner
- Image/Figure: loading=lazy, aspectRatio, sizes props

packages/docs/app/(docs)/components/media/page.tsx

@@ -8,7 +8,7 @@ import {
   BodyText,
   Figure,
   PullQuote,
-} from '@newspaperui/components';
+} from 'newspaperui-components';
 import { Demo } from '@/components/Demo';
 import { PropsTable } from '@/components/PropsTable';