feat(docker): add PostgreSQL database container

.env.example

@@ -0,0 +1,6 @@
+# Backend Environment
+SECRET_KEY=change-me-to-a-long-random-string-in-production
+DB_PASSWORD=change-me-to-a-secure-password
+
+# Optional: PostgreSQL (empfohlen für production)
+# DATABASE_URL wird automatisch gesetzt: postgresql://wrestledesk:DB_PASSWORD@db:5432/wrestledesk

docker-compose.yml

@@ -1,10 +1,25 @@
 version: '3.8'
 
 services:
+  db:
+    image: postgres:15-alpine
+    container_name: wrestledesk-db
+    restart: unless-stopped
+    volumes:
+      - ./postgres-data:/var/lib/postgresql/data
+    environment:
+      - POSTGRES_DB=wrestledesk
+      - POSTGRES_USER=wrestledesk
+      - POSTGRES_PASSWORD=${DB_PASSWORD}
+    networks:
+      - wrestledesk-network
+
   backend:
     build: ./backend
     container_name: wrestledesk-backend
     restart: unless-stopped
+    depends_on:
+      - db
     ports:
       - '10002:8000'
     volumes:
@@ -15,7 +30,7 @@ services:
       - DEBUG=False
       - ALLOWED_HOSTS=localhost,127.0.0.1,rce.playman.top,192.168.101.42,nginx-proxy-manager
       - CORS_ALLOWED_ORIGINS=https://rce.playman.top,http://192.168.101.42:10001,http://192.168.101.42:10002
-      - DATABASE_URL=${DATABASE_URL}
+      - DATABASE_URL=postgresql://wrestledesk:${DB_PASSWORD}@db:5432/wrestledesk
     networks:
       - wrestledesk-network