feat: add PostgreSQL database with Prisma ORM

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 🚀

backend/src/app.js

@@ -27,10 +27,10 @@ app.get('/api/health', (req, res) => {
   });
 });
 
-// API routes (future)
+// API routes
+app.use('/api/events', require('./routes/events'));
 // app.use('/api/auth', require('./routes/auth'));
 // app.use('/api/users', require('./routes/users'));
-// app.use('/api/events', require('./routes/events'));
 // app.use('/api/matches', require('./routes/matches'));
 // app.use('/api/ratings', require('./routes/ratings'));
 

backend/src/routes/events.js

@@ -0,0 +1,71 @@
+const express = require('express');
+const { prisma } = require('../utils/db');
+
+const router = express.Router();
+
+// GET /api/events - List all events
+router.get('/', async (req, res, next) => {
+  try {
+    const events = await prisma.event.findMany({
+      orderBy: {
+        startDate: 'asc',
+      },
+      select: {
+        id: true,
+        name: true,
+        location: true,
+        startDate: true,
+        endDate: true,
+        worldsdcId: true,
+        participantsCount: true,
+        description: true,
+        createdAt: true,
+      },
+    });
+
+    res.json({
+      success: true,
+      count: events.length,
+      data: events,
+    });
+  } catch (error) {
+    next(error);
+  }
+});
+
+// GET /api/events/:id - Get event by ID
+router.get('/:id', async (req, res, next) => {
+  try {
+    const { id } = req.params;
+
+    const event = await prisma.event.findUnique({
+      where: {
+        id: parseInt(id),
+      },
+      include: {
+        chatRooms: true,
+        _count: {
+          select: {
+            matches: true,
+          },
+        },
+      },
+    });
+
+    if (!event) {
+      return res.status(404).json({
+        success: false,
+        error: 'Event not found',
+      });
+    }
+
+    res.json({
+      success: true,
+      data: event,
+    });
+  } catch (error) {
+    next(error);
+  }
+});
+
+module.exports = router;

backend/src/server.js

@@ -1,31 +1,40 @@
 require('dotenv').config();
 const app = require('./app');
+const { testConnection, disconnect } = require('./utils/db');
 
 const PORT = process.env.PORT || 3000;
 
-const server = app.listen(PORT, '0.0.0.0', () => {
-  console.log('=================================');
-  console.log('🚀 spotlight.cam Backend Started');
-  console.log('=================================');
-  console.log(`Environment: ${process.env.NODE_ENV || 'development'}`);
-  console.log(`Server running on port: ${PORT}`);
-  console.log(`Health check: http://localhost:${PORT}/api/health`);
-  console.log('=================================');
+async function startServer() {
+  // Test database connection
+  await testConnection();
+
+  const server = app.listen(PORT, '0.0.0.0', () => {
+    console.log('=================================');
+    console.log('🚀 spotlight.cam Backend Started');
+    console.log('=================================');
+    console.log(`Environment: ${process.env.NODE_ENV || 'development'}`);
+    console.log(`Server running on port: ${PORT}`);
+    console.log(`Health check: http://localhost:${PORT}/api/health`);
+    console.log('=================================');
+  });
+
+  return server;
+}
+
+startServer().catch((err) => {
+  console.error('Failed to start server:', err);
+  process.exit(1);
 });
 
 // Graceful shutdown
-process.on('SIGTERM', () => {
+process.on('SIGTERM', async () => {
   console.log('SIGTERM received, shutting down gracefully...');
-  server.close(() => {
-    console.log('Server closed');
-    process.exit(0);
-  });
+  await disconnect();
+  process.exit(0);
 });
 
-process.on('SIGINT', () => {
+process.on('SIGINT', async () => {
   console.log('SIGINT received, shutting down gracefully...');
-  server.close(() => {
-    console.log('Server closed');
-    process.exit(0);
-  });
+  await disconnect();
+  process.exit(0);
 });

backend/src/utils/db.js

@@ -0,0 +1,41 @@
+const { PrismaClient } = require('@prisma/client');
+
+// Singleton instance of Prisma Client
+let prisma;
+
+if (process.env.NODE_ENV === 'production') {
+  prisma = new PrismaClient();
+} else {
+  // In development, use a global variable to prevent multiple instances
+  // during hot reload
+  if (!global.prisma) {
+    global.prisma = new PrismaClient({
+      log: ['error', 'warn'],
+    });
+  }
+  prisma = global.prisma;
+}
+
+// Test database connection
+async function testConnection() {
+  try {
+    await prisma.$connect();
+    console.log('✅ Database connected successfully');
+    return true;
+  } catch (error) {
+    console.error('❌ Database connection failed:', error.message);
+    return false;
+  }
+}
+
+// Graceful shutdown
+async function disconnect() {
+  await prisma.$disconnect();
+  console.log('Database disconnected');
+}
+
+module.exports = {
+  prisma,
+  testConnection,
+  disconnect,
+};