Hero section component with multiple variants.

Variants:

• split-image: Hero with content on left, image on right
• centered: Centered content with optional background
• minimal: Simple centered text-only hero

Example usage in .phk file:

<Hero variant="split-image">
  <Headline>Build Your SaaS Faster</Headline>
  <Subheadline>Start shipping in days, not months</Subheadline>
  <CTA primary="true" action="/signup">Get Started</CTA>
  <CTA action="#features">Learn More</CTA>
  <Image src="/assets/dashboard.png" alt="Dashboard" />
</Hero>