fix(nginx): ensure nginx starts only after nextcloud is up

Use docker-compose depends_on to guarantee nginx starts after nextcloud
service is initialized. This removes the need for runtime DNS resolution
and simplifies the nginx configuration:

- Remove 'resolver' directive and 'zone' allocations
- Simplify upstream blocks to use direct server references
- Use depends_on: [nextcloud] instead of dynamic resolution
- Keep eurooffice upstream but remove it from dependency chain (optional service)

This ensures nginx starts with a resolvable upstream at startup, preventing
any potential DNS resolution errors during container initialization.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

.docker/nginx/nginx.conf

@@ -28,16 +28,12 @@ http {
     set_real_ip_from  192.168.0.0/16;
     real_ip_header    X-Real-IP;
 
-    resolver 127.0.0.11 valid=10s;
-
     upstream php-backend {
-        zone php-backend 64k;
-        server nextcloud:9000 resolve;
+        server nextcloud:9000;
     }
 
     upstream eurooffice-backend {
-        zone eurooffice-backend 64k;
-        server eurooffice:80 resolve;
+        server eurooffice:80;
     }
 
     # Load HTTP and HTTPS server configurations

docker-compose.yml

@@ -65,6 +65,8 @@ services:
       context: .docker
       dockerfile: Dockerfile.nginx
     restart: unless-stopped
+    depends_on:
+      - nextcloud
     volumes:
       - ./volumes/nextcloud:/var/www/html:ro
       - ./volumes/nginx/includes:/etc/nginx/conf.d/includes/