Update Postiz environment variables for registration control

- Added POSTIZ_DISABLE_REGISTRATION variable to .env.example to manage user registration settings.
- Updated docker-compose.yml to utilize the new environment variable for controlling registration behavior in the Postiz service, enhancing configuration flexibility.

.env.example

@@ -332,6 +332,7 @@ RAGAPP_PASSWORD_HASH=
 POSTIZ_USERNAME=
 POSTIZ_PASSWORD=
 POSTIZ_PASSWORD_HASH=
+POSTIZ_DISABLE_REGISTRATION=false
 
 ############
 # Postiz Social Media Integrations

docker-compose.yml

@@ -615,7 +615,7 @@ services:
       - DATABASE_URL=postgresql://postgres:${POSTGRES_PASSWORD}@postgres:5432/postgres?schema=postiz
       - REDIS_URL=redis://redis:6379
       - JWT_SECRET=${JWT_SECRET}
-      - DISABLE_REGISTRATION=true
+      - DISABLE_REGISTRATION=${POSTIZ_DISABLE_REGISTRATION}
       - FRONTEND_URL=${POSTIZ_HOSTNAME:+https://}${POSTIZ_HOSTNAME}
       - NEXT_PUBLIC_BACKEND_URL=${POSTIZ_HOSTNAME:+https://}${POSTIZ_HOSTNAME}
       - BACKEND_INTERNAL_URL=http://postiz:3000