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

scripts/setup.js

@@ -0,0 +1,75 @@
+#!/usr/bin/env node
+
+const { execSync } = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+console.log('🎨 Setting up GaPlace...\n');
+
+// Check if required files exist
+const requiredFiles = [
+  'backend/.env',
+  'frontend/.env.local'
+];
+
+console.log('📋 Checking environment files...');
+requiredFiles.forEach(file => {
+  if (!fs.existsSync(file)) {
+    console.log(`❌ Missing: ${file}`);
+    process.exit(1);
+  } else {
+    console.log(`✅ Found: ${file}`);
+  }
+});
+
+// Build shared package
+console.log('\n📦 Building shared package...');
+try {
+  execSync('npm run build', { cwd: 'shared', stdio: 'inherit' });
+  console.log('✅ Shared package built successfully');
+} catch (error) {
+  console.error('❌ Failed to build shared package');
+  process.exit(1);
+}
+
+// Install dependencies for all workspaces
+console.log('\n📦 Installing dependencies...');
+try {
+  execSync('npm install', { stdio: 'inherit' });
+  console.log('✅ Dependencies installed successfully');
+} catch (error) {
+  console.error('❌ Failed to install dependencies');
+  process.exit(1);
+}
+
+// Build backend
+console.log('\n🔧 Building backend...');
+try {
+  execSync('npm run build', { cwd: 'backend', stdio: 'inherit' });
+  console.log('✅ Backend built successfully');
+} catch (error) {
+  console.error('❌ Failed to build backend');
+  process.exit(1);
+}
+
+// Build frontend
+console.log('\n🎨 Building frontend...');
+try {
+  execSync('npm run build', { cwd: 'frontend', stdio: 'inherit' });
+  console.log('✅ Frontend built successfully');
+} catch (error) {
+  console.error('❌ Failed to build frontend');
+  process.exit(1);
+}
+
+console.log('\n🚀 Setup complete! To start development:');
+console.log('');
+console.log('1. Start databases:');
+console.log('   docker-compose up redis postgres -d');
+console.log('');
+console.log('2. Start development servers:');
+console.log('   npm run dev');
+console.log('');
+console.log('3. Open http://localhost:3000 in your browser');
+console.log('');
+console.log('🎨 Welcome to GaPlace! ✨');