feat: Implement proper Three.js logo system with custom environment mapping

- Replace CDN-based Three.js with npm packages for reliable loading
- Add DRACO loader support for compressed GLB files
- Implement custom horizon gradient environment mapping
- Use exact material properties from reference logo.html (MeshPhysicalMaterial)
- Apply proper metallic sheen, clearcoat, and reflectivity settings
- Fix camera positioning and canvas sizing to prevent clipping
- Maintain square aspect ratio for consistent logo display
- Load user's mobius-ring.glb with fallback torus geometry

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

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

brand-assets/brand-style-guide-site/public/vercel.svg

@@ -0,0 +1 @@
+<svg fill="none" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1155 1000"><path d="m577.3 0 577.4 1000H0z" fill="#fff"/></svg>