Fix file viewer: block name mismatch (extra_scripts → scripts)

agent_generator_pkg/src/agent_generator/web/templates/result.html

@@ -213,7 +213,7 @@ var _framework = "{{ plan.framework }}";
 </script>
 {% endblock %}
 
-{% block extra_scripts %}
+{% block scripts %}
 <script>
     const fileData = JSON.parse(document.getElementById('fileData').textContent);
     const firstFile = Object.keys(fileData)[0];

app/templates/result.html

@@ -213,7 +213,7 @@ var _framework = "{{ plan.framework }}";
 </script>
 {% endblock %}
 
-{% block extra_scripts %}
+{% block scripts %}
 <script>
     const fileData = JSON.parse(document.getElementById('fileData').textContent);
     const firstFile = Object.keys(fileData)[0];