(bugfix) Fix hosts file configuration by using extra_hosts at runtime

Docker overwrites /etc/hosts at container runtime, so copying it during
build (COPY command) or mounting it as volume doesn't work reliably.
Moved to extra_hosts in docker-compose files for both standalone and
swarm deployments.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docker-stack/docker-compose-swarm.yml

@@ -17,8 +17,11 @@ services:
     networks:
       - traefik-network
       - util-bills-mongo-network
-    volumes:
-      - ./web-app/etc/hosts/:/etc/hosts
+    # NextJS will do name resolution for `rezije.app` and will crash if it
+    # resolves to an IP adress different from the one assigned to the Docker container.
+    # This will prevent that from happening.
+    extra_hosts:
+      - "rezije.app:0.0.0.0"
     environment:
       MONGODB_URI: mongodb://rezije.app:w4z4piJBgCdAm4tpawqB@mongo:27017/utility-bills
       GOOGLE_ID: 355397364527-adjrokm6hromcaaar0qfhk050mfr35ou.apps.googleusercontent.com