feat: add avatars, live leaderboard, and rotated puzzle difficulty

[abdullahyousuf54]

Summary

This PR introduces several gameplay and user-experience enhancements to CrowdPlay, focusing on player personalization, competitive engagement, and puzzle difficulty progression.

Features Added

🎭 Custom Player Avatars

• Integrated DiceBear-based avatar generation and customization.
• Added avatar selection during player onboarding.
• Avatars are displayed across gameplay interfaces, including player lists and leaderboards.
• Supports avatar personalization through multiple appearance options.

🏆 Real-Time Live Leaderboard

• Added a live leaderboard on the shared screen experience.
• Displays player rank, avatar, name, and score.
• Updates dynamically in real time using existing Socket.IO infrastructure.
• Includes automatic ranking and spectator-friendly presentation.

🧩 Rotated Puzzle Difficulty Mode

• Added difficulty selection during game setup.
• Introduced a new "Rotated Pieces" mode alongside the existing simple mode.
• Puzzle pieces can spawn at random orientations.
• Added free-angle piece rotation support.
• Placement validation now considers both position and orientation using a configurable tolerance system.
• Preserves backward compatibility with the original gameplay flow.

📖 Documentation

• Updated README with detailed documentation of all newly added features.
• Added screenshots and feature showcase sections.

Technical Notes

• Reused the existing game architecture, Socket.IO communication flow, and puzzle validation logic wherever possible.
• Maintained backward compatibility with existing rooms, gameplay mechanics, and multiplayer synchronization.
• No breaking changes introduced.

Testing

• Verified avatar selection and display across game screens.
• Verified real-time leaderboard updates during gameplay.
• Tested both Simple and Rotated difficulty modes.
• Confirmed correct puzzle validation with orientation tolerance.
• Verified existing gameplay flow remains unaffected in Simple mode.