Modernize collaborative pixel art platform to production-ready architecture

Major refactor from simple HTML/JS app to modern full-stack TypeScript application:

## Architecture Changes
- Migrated to monorepo structure with workspaces (backend, frontend, shared)
- Backend: Node.js + Express + TypeScript + Socket.IO
- Frontend: Next.js 15.5 + React 19 + TypeScript + Tailwind CSS
- Shared: Common types and utilities across packages

## Key Features Implemented
- Real-time WebSocket collaboration via Socket.IO
- Virtual canvas with chunked loading for performance
- Modern UI with dark mode and responsive design
- Mock database system for easy development (Redis/PostgreSQL compatible)
- Comprehensive error handling and rate limiting
- User presence and cursor tracking
- Infinite canvas support with zoom/pan controls

## Performance Optimizations
- Canvas virtualization - only renders visible viewport
- Chunked pixel data loading (64x64 pixel chunks)
- Optimized WebSocket protocol
- Memory-efficient state management with Zustand

## Development Experience
- Full TypeScript support across all packages
- Hot reload for both frontend and backend
- Docker support for production deployment
- Comprehensive linting and formatting
- Automated development server startup

## Fixed Issues
- Corrected start script paths
- Updated environment configuration
- Fixed ESLint configuration issues
- Ensured all dependencies are properly installed
- Verified build process works correctly

frontend/next.config.js

@@ -0,0 +1,30 @@
+/** @type {import('next').NextConfig} */
+const nextConfig = {
+  images: {
+    remotePatterns: [
+      {
+        protocol: 'http',
+        hostname: 'localhost',
+        port: '3001',
+        pathname: '/**',
+      },
+      {
+        protocol: 'http',
+        hostname: '192.168.1.110',
+        port: '3001',
+        pathname: '/**',
+      },
+    ],
+  },
+  allowedDevOrigins: ['192.168.1.110:3000', '192.168.1.110'],
+  async rewrites() {
+    return [
+      {
+        source: '/api/:path*',
+        destination: `${process.env.NEXT_PUBLIC_BACKEND_URL || 'http://localhost:3001'}/api/:path*`,
+      },
+    ];
+  },
+};
+
+module.exports = nextConfig;