Refactor Shopware role to use dedicated OpenSearch service and improved environment handling.

Changes include:
- Added OpenSearch configuration and variable definitions (image, version, heap, memory limits)
- Replaced legacy search/elasticsearch logic with OpenSearch integration
- Updated docker-compose template for OpenSearch with proper JVM heap and ulimits
- Ensured both OPENSEARCH_URL and ELASTICSEARCH_URL are set for compatibility

Reference: https://chatgpt.com/share/6907b0d4-ab14-800f-b576-62c0d26c8ad1

roles/web-app-shopware/templates/env.j2

@@ -19,13 +19,11 @@ MESSENGER_TRANSPORT_DSN="redis://{{ SHOPWARE_REDIS_ADDRESS }}/2"
 CACHE_URL="file://cache"
 {% endif %}
 
+
+{% if SHOPWARE_OPENSEARCH_ENABLED %}
 # Search
-{% if SHOPWARE_SEARCH_ENABLED %}
-{% if SHOPWARE_SEARCH_ENGINE == 'opensearch' %}
 OPENSEARCH_URL="http://opensearch:9200"
-{% else %}
-ELASTICSEARCH_URL="http://elasticsearch:9200"
-{% endif %}
+ELASTICSEARCH_URL="http://opensearch:9200"
 {% endif %}
 
 # Mail (Mailu)