nav: add AOS Rankings link to header navigation

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

public/header.html

@@ -29,6 +29,7 @@
     <div class="navbar-center hidden lg:flex flex-1 justify-center">
       <ul class="menu menu-horizontal px-1 gap-1">
         <li><a href="/index.html">40K Rankings</a></li>
+        <li><a href="https://aos-rankings.gateway-gamers.net">AOS Rankings</a></li>
       </ul>
     </div>
     <div class="navbar-end gap-2 ml-auto">
@@ -49,6 +50,7 @@
         </label>
         <ul tabindex="0" class="menu menu-sm dropdown-content mt-3 z-[1] p-2 shadow bg-base-200 rounded-box w-52">
           <li><a href="/index.html">40K Rankings</a></li>
+          <li><a href="https://aos-rankings.gateway-gamers.net">AOS Rankings</a></li>
         </ul>
       </div>
     </div>