Reverted matrix fix

roles/sys-svc-compose/templates/networks.yml.j2

@@ -41,15 +41,19 @@ networks:
   {{ _ollama_network_name }}:
     external: true
 {% endif %}
-{# Default network is pre-created externally by
-   sys-svc-compose/tasks/utils/network/create.yml (docker_network), so
-   declare it `external: true` to keep compose out of its lifecycle. #}
+{# Default Network — the subnet lives at
+   roles/<role>/meta/server.yml.networks.local.subnet, materialised at
+   applications.<role>.server.networks.local.subnet. #}
 {% set _default_subnet = lookup('config', application_id, 'server.networks.local.subnet', '') %}
 {% if not application_id.startswith('svc-db-') and not application_id.startswith('svc-ai-') %}
   default:
 {% if _default_subnet %}
     name: {{ application_id | get_entity_name }}
-    external: true
+    driver: bridge
+    ipam:
+      driver: default
+      config:
+        - subnet: {{ _default_subnet }}
 {% endif %}
 {% endif %}
 {{ "\n" }}