- Add 3 new database tables: divisions, competition_types, event_user_heats
- Add seed data for 6 divisions (NEW, NOV, INT, ADV, ALL, CHA) and 2 competition types (J&J, STR)
- Add API endpoints for divisions and competition types
- Add heats management endpoints in events route (POST/GET/DELETE)
- Implement unique constraint: cannot have same role in same division+competition type
- Add participant verification before allowing heats management
- Support heat numbers 1-9 with optional Leader/Follower role
Phase 1 - Step 2: PostgreSQL Setup
**Infrastructure:**
- Add PostgreSQL 15 Alpine container to docker-compose.yml
- Configure persistent volume for database data
- Update backend Dockerfile with OpenSSL for Prisma compatibility
**Database Schema (Prisma):**
- 6 tables: users, events, chat_rooms, messages, matches, ratings
- Foreign key relationships and cascading deletes
- Performance indexes on frequently queried columns
- Unique constraints for data integrity
**Prisma Setup:**
- Prisma Client for database queries
- Migration system with initial migration
- Seed script with 4 test events and chat rooms
- Database connection utility with singleton pattern
**API Implementation:**
- GET /api/events - List all events (with filtering and sorting)
- GET /api/events/:id - Get single event with relations
- Database connection test on server startup
- Graceful database disconnect on shutdown
**Seed Data:**
- Warsaw Dance Festival 2025
- Swing Camp Barcelona 2025
- Blues Week Herräng 2025
- Krakow Swing Connection 2025
**Testing:**
- Database connection verified ✅
- API endpoints returning data from PostgreSQL ✅
- Migrations applied successfully ✅
All systems operational 🚀
