feat: integrate WebAssembly for zero-latency, offline-first color operations

Replaced REST API dependency with @valknarthing/pastel-wasm (130KB) for
complete browser-based color operations. The application is now fully
static (2.2MB total) with zero network latency and offline support.

**Key Changes:**

1. **WASM Integration:**
   - Added @valknarthing/pastel-wasm dependency (0.1.0)
   - Created lib/api/wasm-client.ts wrapper matching API interface
   - Updated lib/api/client.ts to use WASM client by default
   - All 18 color operations now run locally in browser

2. **Static Export Configuration:**
   - Changed next.config.ts output from 'standalone' to 'export'
   - Disabled image optimization for static export
   - Removed API proxy route (app/api/pastel/[...path]/route.ts)
   - Updated package.json scripts (removed dev:api, added serve)

3. **Docker Optimization:**
   - Migrated from Node.js standalone to nginx-alpine
   - Created nginx.conf with SPA routing and WASM mime types
   - Updated Dockerfile for static file serving
   - Reduced image size from ~150MB to ~25MB
   - Changed port from 3000 to 80 (standard HTTP)
   - Simplified docker-compose.yml (removed pastel-api service)

4. **Documentation Updates:**
   - Updated README.md with WASM benefits and deployment options
   - Added Key Benefits section highlighting zero-latency features
   - Rewrote deployment section for static hosting platforms
   - Updated CLAUDE.md tech stack and architecture
   - Removed obsolete docs: DEV_SETUP.md, DOCKER.md, IMPLEMENTATION_PLAN.md

**Benefits:**
- 🚀 Zero Latency - All operations run locally via WebAssembly
- 📱 Offline First - Works completely offline after initial load
- 🌐 No Backend - Fully static, deploy anywhere
- ⚡ Fast - Native-speed color operations in browser
- 📦 Small - 2.2MB total (130KB WASM, 2.07MB HTML/CSS/JS)

**Deployment:**
Can now be deployed to any static hosting platform:
- Vercel, Netlify, Cloudflare Pages (zero config)
- GitHub Pages, S3, CDN
- Self-hosted nginx/Apache
- Docker (optional, nginx-based)

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

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

package.json

@@ -9,10 +9,9 @@
   "scripts": {
     "dev": "next dev",
     "dev:turbo": "next dev --turbopack",
-    "dev:api": "cd ../pastel-api && cargo run",
-    "dev:all": "pnpm run dev:api & pnpm run dev",
     "build": "next build",
-    "start": "next start",
+    "export": "next build",
+    "serve": "pnpm build && npx serve out",
     "lint": "next lint",
     "lint:fix": "next lint --fix",
     "format": "prettier --write \"**/*.{js,jsx,ts,tsx,json,css,md}\"",
@@ -25,6 +24,7 @@
   },
   "dependencies": {
     "@tanstack/react-query": "^5.62.11",
+    "@valknarthing/pastel-wasm": "^0.1.0",
     "clsx": "^2.1.1",
     "cmdk": "^1.0.4",
     "framer-motion": "^11.15.0",