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

package.json

@@ -1,18 +1,50 @@
 {
-  "dependencies": {
-    "cookie-parser": "^1.4.6",
-    "express": "^4.18.2",
-    "fs": "^0.0.1-security",
-    "socket.io": "^4.7.1"
-  },
-  "name": "collaborative-pixel-art",
-  "version": "1.0.0",
-  "main": "server.js",
+  "name": "gaplace",
+  "version": "2.0.0",
+  "description": "Modern collaborative pixel art platform with real-time collaboration and infinite canvas",
+  "private": true,
+  "workspaces": [
+    "backend",
+    "frontend",
+    "shared"
+  ],
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "dev": "node scripts/start-dev.js",
+    "dev:old": "concurrently \"npm run dev:backend\" \"npm run dev:frontend\"",
+    "dev:backend": "npm run dev --workspace=backend",
+    "dev:frontend": "npm run dev --workspace=frontend",
+    "build": "npm run build --workspace=backend && npm run build --workspace=frontend",
+    "start": "npm run start --workspace=backend",
+    "test": "npm run test --workspaces",
+    "lint": "npm run lint --workspaces",
+    "type-check": "npm run type-check --workspaces",
+    "clean": "npm run clean --workspaces && rm -rf node_modules",
+    "setup": "node scripts/setup.js"
   },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "description": ""
-}
+  "devDependencies": {
+    "concurrently": "^9.1.2",
+    "@typescript-eslint/eslint-plugin": "^8.22.0",
+    "@typescript-eslint/parser": "^8.22.0",
+    "eslint": "^8.57.1",
+    "eslint-config-prettier": "^9.1.0",
+    "eslint-plugin-prettier": "^5.2.1",
+    "prettier": "^3.4.2",
+    "typescript": "^5.7.3"
+  },
+  "engines": {
+    "node": ">=18.0.0",
+    "npm": ">=9.0.0"
+  },
+  "keywords": [
+    "pixel-art",
+    "collaborative",
+    "real-time",
+    "canvas",
+    "websocket",
+    "react",
+    "nextjs",
+    "typescript"
+  ],
+  "author": "GaPlace Team",
+  "license": "MIT"
+}