Add reusable HTTP healthcheck template and integrate into Shopware and Taiga roles

roles/docker-container/templates/healthcheck/http.yml.j2

@@ -0,0 +1,31 @@
+{# ------------------------------------------------------------------------------
+  Healthcheck: HTTP Local
+  ------------------------------------------------------------------------------
+  This template defines a generic HTTP healthcheck for containers exposing
+  a web service on a local port (e.g., Nginx, Apache, PHP-FPM, Shopware, etc.).
+
+  It uses `wget` or `curl` (as fallback) to test if the container responds on
+  http://127.0.0.1:{{ container_port }}/. If the request succeeds, Docker marks
+  the container as "healthy"; otherwise, as "unhealthy".
+
+  Parameters:
+    - container_port: The internal port the service listens on.
+
+  Timing:
+    - interval:      30s   → Check every 30 seconds
+    - timeout:        5s   → Each check must complete within 5 seconds
+    - retries:        5    → Mark unhealthy after 5 consecutive failures
+    - start_period:  20s   → Grace period before health checks begin
+
+  Usage:
+  {% filter indent(4) %}
+      {% include 'roles/docker-container/templates/healthcheck/http.yml.j2' %}
+  {% endfilter %}
+  ------------------------------------------------------------------------------
+#}
+healthcheck:
+  test: ["CMD-SHELL", "wget -qO- http://127.0.0.1:{{ container_port }}/ >/dev/null || curl -fsS http://127.0.0.1:{{ container_port }}/ >/dev/null"]
+  interval: 30s
+  timeout: 5s
+  retries: 5
+  start_period: 20s