Implement Excalidraw Backend Services

[saqib001-github]

Implementing backend services for Excalidraw clone including:

• WebSocket Backend for real-time collaboration
• HTTP Backend with user authentication
• Database setup with Prisma
• Shared utilities package
• API Testing endpoints

Technical Details:

• User authentication with JWT
• Real-time room management
• Prisma schema for Users, Rooms, and Chats
• REST API endpoints for user operations