Add jq to Docker image and improve UNIT_SOURCE handling

- Include jq in the Docker image for JSON processing.
- Refactor UNIT_SOURCE logic to cleanly update configuration using jq.
- Remove obsolete UNIT_SOURCE handling code.

docker-compose-prod.yml

@@ -16,7 +16,7 @@ services:
       - ./app/application:/var/www/html
     environment:
       CONTAINER_ROLE: app
-      UNIT_SOURCE: '"172.16.0.0/12"'
+      UNIT_SOURCE: "172.16.0.0/12"
 
   queue:
     build: