refactor(hero): remove metrics block from hero section

The projects/categories/topic groups stats added visual clutter to the
hero without contributing to the core purpose of the section.

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

website/templates/index.html

@@ -47,21 +47,6 @@
             >View on GitHub</a
           >
         </div>
-
-        <dl class="hero-metrics" aria-label="Site overview">
-          <div>
-            <dt>{{ "{:,}".format(entries | length) }}</dt>
-            <dd>projects</dd>
-          </div>
-          <div>
-            <dt>{{ total_categories }}</dt>
-            <dd>categories</dd>
-          </div>
-          <div>
-            <dt>{{ groups | length }}</dt>
-            <dd>topic groups</dd>
-          </div>
-        </dl>
       </div>
     </div>