feat: rebuild demo with glassmorphism, Space Grotesk, spring-physics animations

- Glassmorphism cards with backdrop-filter:blur(16px)
- Space Grotesk headings + DM Sans body + JetBrains Mono code
- Spring-physics cubic-bezier animations (overshoot easing)
- Hover-to-reveal pipeline stages
- Animated scan bar on document
- Vector embedding bar visualization per chunk
- Database store with dot insertion animation
- Real-time keyword search with highlighted matches
- Terminal-style code panel that mirrors the pipeline
- 4 sample data loaders (Code, Docs, API)
- Step indicator with active/completed states
- Fixed nav bar with glassmorphism
- Hero with gradient badge
- CTA footer with GitHub/Install/Compare links

Author: abhayjnayakk