Add landing page enhancements, API docs fix, and deployment guide

- Animated workflow diagram with 5-step pipeline (CSS animations)
- 4 real-world use case cards with metrics and references
- Tech highlights section (Rust, Algorithms, Languages, GPU)
- Fix SPA catch-all to expose /docs, /redoc, /openapi.json
- Comprehensive DEPLOYMENT.md with Docker, NGINX, SSL, K8s, backup

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: eprifti