fix(homepage): widen skill cards container to 650px

Increased the "What You'll Learn" container width from 420px to 650px
to give the 2-column grid of skill cards proper breathing room and
prevent cramped layouts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/src/app/page.tsx

@@ -188,7 +188,7 @@ export default function HomePage() {
                   <div
                     className={css({
                       flex: '0 0 auto',
-                      w: { base: '100%', md: '420px' },
+                      w: { base: '100%', md: '650px' },
                     })}
                   >
                     <h3