perf: remove framer-motion and lucide-react from critical path

- Remove framer-motion from Hero.tsx and HeaderClient.tsx, replace with CSS animations/transitions
- Replace lucide-react icons (Menu, X, Mail) with inline SVGs in HeaderClient.tsx
- Lazy-load About, Projects, Contact, Footer via dynamic() imports in ClientWrappers.tsx
- Defer ShaderGradient/BackgroundBlobs loading via requestIdleCallback in ClientProviders.tsx
- Remove AnimatePresence page wrapper that caused full re-renders
- Enable experimental.optimizeCss (critters) for critical CSS inlining
- Add fadeIn keyframe to Tailwind config for CSS-based animations

Homepage JS reduced from 563KB to 438KB (-125KB).
Eliminates ~39s main thread work from WebGL init and layout thrashing.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

next.config.ts

@@ -34,6 +34,7 @@ const nextConfig: NextConfig = {
   experimental:
     process.env.NODE_ENV === "production"
       ? {
+          optimizeCss: true,
           optimizePackageImports: ["lucide-react", "framer-motion", "three", "@react-three/fiber"],
         }
       : {