update PostgreSQL configuration in deployment files (#365)

- Change PostgreSQL volume mount from /var/lib/postgresql/data to /var/lib/postgresql
  This allows PostgreSQL to manage the data directory structure internally

- Add PostgreSQL version configuration variable to all docker-compose files:
  * POSTGRES_VERSION for deployment/nginx
  * APPSEC_POSTGRES_VERSION for all deployment/docker-compose variants

- Update PostgreSQL image tag to use version variable (set to version 18)
  Changed from 'postgres' to 'postgres:' or 'postgres:'

- Add PostgreSQL version variable to all .env files with default value of 18

Co-authored-by: Nahum Perman <nahump@checkpoint.com>

deployment/nginx/.env

@@ -15,6 +15,7 @@ USER_EMAIL=user@email.com
 DB_PASSWORD=pass
 DB_USER=postgres
 DB_HOST=appsec-db
+POSTGRES_VERSION=18
 POSTGRES_STORAGE=./postgres-data
 NGINX_CONF_DIR=./nginx-proxy-config
 

deployment/nginx/docker-compose.yaml

@@ -81,14 +81,14 @@ services:
   appsec-db:
     profiles:
       - standalone
-    image: postgres
+    image: postgres:${POSTGRES_VERSION}
     container_name: appsec-db
     restart: always
     environment:
       - POSTGRES_PASSWORD=${DB_PASSWORD}
       - POSTGRES_USER=${DB_USER} 
     volumes:
-      - ${POSTGRES_STORAGE}:/var/lib/postgresql/data
+      - ${POSTGRES_STORAGE}:/var/lib/postgresql
 
 ## example juice-shop backend container (vulnerable webserver, USE ONLY FOR TESTING AND IN LAB ENV)
 ##