Fix prev/next nav showing on section landing pages

Section landing pages (parent: '/') are not sequential content,
but prev/next treated all top-level pages as siblings. This caused
/about/ to show Publishing Events and Calendar Spam as neighbors.

Skip prev/next for pages with parent='/'.

Author: ronaldtse

_layouts/toc-type.html

@@ -73,7 +73,8 @@ <h1 class="text-3xl font-bold text-gray-900 dark:text-white mb-6">{{ page.title
             </div>
         {% endif %}
 
-        {% comment %}Prev/Next navigation{% endcomment %}
+        {% comment %}Prev/Next navigation — skip for top-level section landing pages{% endcomment %}
+        {% unless page.parent == "/" %}
         {% assign siblingPages = site.pages | where: "parent", page.parent | sort: "order" %}
         {% if siblingPages.size > 1 %}
             {% assign prevPage = nil %}
@@ -107,6 +108,7 @@ <h1 class="text-3xl font-bold text-gray-900 dark:text-white mb-6">{{ page.title
             </div>
             {% endif %}
         {% endif %}
+        {% endunless %}
 
         <a href="https://github.com/CalConnect/DEVGUIDE/edit/main/{{ page.path }}" class="edit-on-github" target="_blank" rel="noopener">
             <svg viewBox="0 0 16 16" fill="currentColor"><path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0016 8c0-4.42-3.58-8-8-8z"/></svg>