Add Seasonal Events and Limited-Time Puzzle System

[vic-Gray]

🧩 Seasonal Events & Limited-Time Puzzles

This PR introduces a seasonal events system that enables time-limited puzzles, exclusive rewards, and competitive leaderboards. The system is fully automated and designed to scale for future events without refactoring core game logic.

✨ What’s Included
⏰ Event Scheduling

Automated activation and deactivation of events based on start/end dates

Cron-based scheduler ensures no manual intervention

🧩 Event-Specific Puzzles

Puzzles are tied to specific events and categories

Only puzzles from active events are accessible

🔒 Time-Limited Availability

Backend enforcement prevents access to puzzles outside event windows

🎁 Seasonal Rewards

Rewards distributed based on puzzle completion and score thresholds

Supports extensible reward types (points, badges, future NFTs)

🏆 Event Leaderboards

Per-event leaderboard ranking players by score

Top performers can be queried efficiently

📢 Event Announcements

Centralized announcement system for event updates and notifications

📊 Player Event History

Tracks player participation, completed puzzles, scores, and rewards

Enables historical event insights per player

✅ Acceptance Criteria Met

✔ Events start and end automatically

✔ Exclusive puzzles available only during active events

✔ Seasonal rewards distributed correctly

✔ Player event history fully tracked

🛠️ Technical Notes

Built with NestJS and TypeORM

Blockchain-agnostic and ready for future integrations

Clean separation of concerns between events, puzzles, players, and rewards

[Mkalbani]

Please resolve conflict @vic-Gray