feat: add footer rendering and custom-html sidebar widget

- Homepage builder now renders footer section below main content
- Sidebar supports custom-html widget type with title + content
- New homepage-footer.njk component for footer items

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

_includes/components/homepage-builder.njk

@@ -81,3 +81,6 @@
   </div>
 
 {% endif %}
+
+{# Footer — rendered after the main layout, full width #}
+{% include "components/homepage-footer.njk" %}

_includes/components/homepage-footer.njk

@@ -0,0 +1,23 @@
+{# Homepage Builder Footer — renders footer items from homepageConfig.footer #}
+{% if homepageConfig.footer and homepageConfig.footer.length %}
+<footer class="homepage-footer mt-8 sm:mt-12 pt-6 sm:pt-8 border-t border-surface-200 dark:border-surface-700">
+  {% for section in homepageConfig.footer %}
+    {% if section.type == "custom-html" %}
+      {% set sectionConfig = section.config or {} %}
+      <div class="mb-6">
+        {% if sectionConfig.title %}
+        <h3 class="text-lg font-semibold text-surface-900 dark:text-surface-100 mb-3">{{ sectionConfig.title }}</h3>
+        {% endif %}
+        {% if sectionConfig.content %}
+        <div class="prose dark:prose-invert max-w-none">
+          {{ sectionConfig.content | safe }}
+        </div>
+        {% endif %}
+      </div>
+    {% else %}
+      {# For non-custom sections, use the section dispatcher #}
+      {% include "components/homepage-section.njk" %}
+    {% endif %}
+  {% endfor %}
+</footer>
+{% endif %}

_includes/components/homepage-sidebar.njk

@@ -28,6 +28,19 @@
           });
         </script>
       </div>
+    {% elif widget.type == "custom-html" %}
+      {# Custom content widget #}
+      {% set wConfig = widget.config or {} %}
+      <div class="sidebar-widget">
+        {% if wConfig.title %}
+        <h3 class="text-sm font-semibold text-surface-600 dark:text-surface-400 uppercase tracking-wide mb-3">{{ wConfig.title }}</h3>
+        {% endif %}
+        {% if wConfig.content %}
+        <div class="prose dark:prose-invert prose-sm max-w-none">
+          {{ wConfig.content | safe }}
+        </div>
+        {% endif %}
+      </div>
     {% else %}
       <!-- Unknown widget type: {{ widget.type }} -->
     {% endif %}