Improve settings hierarchy conciseness

core/templates/partials/ai-execution-run-detail-tab.html

@@ -0,0 +1,7 @@
+{% if tab_slug == "error" %}
+  {% if run.error %}
+    <pre style="white-space: pre-wrap; margin: 0;">{{ run.error }}</pre>
+  {% else %}
+    <p class="has-text-grey">No error recorded for this run.</p>
+  {% endif %}
+{% endif %}