- Add 'image' front matter parameter for article thumbnails
- Redesign article-list-item.html as semantic article card:
- Large thumbnail (aspect-video, object-cover) at top if image is present
- Title linked to article page
- Publication date and type badge
- Excerpt (from .Description or .Summary with plainify)
- "Read more" CTA button with arrow icon and hover animation
- Increase list container width (max-w-2xl → max-w-3xl) and spacing (space-y-2 → space-y-6)
- Thumbnail image has subtle scale-up hover effect
- Arrow icon animates on hover
- All three clickable elements (.image, title, CTA) link to article
