refactor: update Nginx configuration and Docker setup

- Change user directive in Nginx configuration from 'nginx' to 'www-data'.
- Update upstream server configurations in Nginx to use 'localhost' instead of service names.
- Modify Nginx server block to redirect HTTP to a status page instead of Grafana.
- Rename Alertmanager location from '/alertmanager/' to '/alerts/' for consistency.
- Remove deprecated status page configuration and related files.
- Adjust Prometheus configuration to reflect the new Docker network settings.

docker-compose.yml

@@ -39,7 +39,6 @@ services:
       - GF_INSTALL_PLUGINS=grafana-clock-panel,grafana-simple-json-datasource
       - GF_SERVER_ROOT_URL=https://${SERVER_IP}/grafana/
       - GF_SERVER_SERVE_FROM_SUB_PATH=true
-      - GF_SERVER_DOMAIN=${SERVER_IP}
     ports:
       - "3000:3000"
     volumes:
@@ -111,7 +110,7 @@ services:
     environment:
       - SERVER_IP=${SERVER_IP}
     volumes:
-      - ./infra/nginx/nginx.conf:/etc/nginx/templates/nginx.conf.template:ro
+      - ./infra/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
       - ./infra/nginx/conf.d:/etc/nginx/conf.d:ro
       - ./infra/nginx/ssl:/etc/nginx/ssl:ro
       - ./infra/nginx/.htpasswd:/etc/nginx/.htpasswd:ro
@@ -255,4 +254,5 @@ networks:
     driver: bridge
     ipam:
       config:
-        - subnet: 192.168.100.0/24
+        - subnet: 172.20.0.0/16
+          gateway: 172.20.0.1