feat: add postgres database service to docker-compose

docker-compose.yaml

@@ -16,13 +16,27 @@ services:
     build:
       context: ./backend
     volumes:
-      - data-volume:/app/data
       - uploads-volume:/app/uploads
     environment:
       - NODE_ENV=production
+      - DATABASE_URL=postgresql://titan_user:titan_secure_pass@db:5432/titan_db
+    depends_on:
+      - db
+    labels:
+      - "traefik.enable=false"
+
+  db:
+    image: postgres:16-alpine
+    restart: always
+    environment:
+      - POSTGRES_USER=titan_user
+      - POSTGRES_PASSWORD=titan_secure_pass
+      - POSTGRES_DB=titan_db
+    volumes:
+      - db-data:/var/lib/postgresql/data
     labels:
       - "traefik.enable=false"
 
 volumes:
-  data-volume:
   uploads-volume:
+  db-data: