Consolidate gateway-gamers sites, dedupe shared header/footer/images

Merge the four independent gateway-gamers.net site repos (40k-rankings,
aos-rankings, kingmaker, scouting) into one monorepo under sites/,
preserving each site's full commit history via a manual subtree-style
merge (git-subtree isn't available in this environment).

- shared/: header.template.html (nav swapped in per site), footer.html,
  and images/ — previously byte-identical copies duplicated 4x (~100MB).
- Each site's public/footer.html and public/images are now symlinks into
  shared/; public/header.html is generated at predev/prebuild time from
  shared/header.template.html + the site's own nav.html, so nav bars stay
  individual while everything else about the header is shared.
- Single root .gitlab-ci.yml with path-scoped build/deploy jobs per site
  plus a deploy:shared job, replacing the 4 separate per-repo pipelines.
- nginx confs (kept per-site as reference, same as before) gain
  location /images/ and location = /footer.html alias blocks pointing at
  a shared webserver directory, so the deployed site no longer duplicates
  the images either — see README.md for the full layout and the runbook
  for applying this on the webserver.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SBzcNkW7JcYipnAX6HfgmK

shared/footer.html

@@ -0,0 +1,3 @@
+<footer class="footer footer-center bg-base-300 text-base-content p-4">
+  <p>&copy; 2026 Gateway Gamers. All rights reserved.</p>
+</footer>

shared/header.template.html

@@ -0,0 +1,57 @@
+<header class="bg-base-300 shadow-lg">
+
+  <!-- Hero: carousel background + centered logo -->
+  <div class="relative overflow-hidden min-h-64 py-10 flex items-center justify-center">
+
+    <!-- Carousel images -->
+    <div id="hero-carousel" class="absolute inset-0">
+      <img src="/images/photo1.jpg" class="carousel-slide absolute inset-0 w-full h-full object-cover opacity-0 transition-opacity duration-1000" />
+      <img src="/images/photo2.jpg" class="carousel-slide absolute inset-0 w-full h-full object-cover opacity-0 transition-opacity duration-1000" />
+      <img src="/images/photo3.jpg" class="carousel-slide absolute inset-0 w-full h-full object-cover opacity-0 transition-opacity duration-1000" />
+      <img src="/images/photo4.jpg" class="carousel-slide absolute inset-0 w-full h-full object-cover opacity-0 transition-opacity duration-1000" />
+      <img src="/images/photo5.jpg" class="carousel-slide absolute inset-0 w-full h-full object-cover opacity-0 transition-opacity duration-1000" />
+    </div>
+
+    <!-- Overlay so logo stays readable over busy images -->
+    <div class="absolute inset-0 bg-black/40"></div>
+
+    <!-- Logo -->
+    <div class="relative z-10">
+      <a href="/index.html">
+        <img src="/images/logo.png" alt="Gateway Gamers" class="h-48 w-auto drop-shadow-2xl" />
+      </a>
+    </div>
+
+  </div>
+
+  <!-- Nav row -->
+  <div class="navbar bg-base-200 px-4 min-h-0 py-2">
+    <div class="navbar-center hidden lg:flex flex-1 justify-center">
+      <ul class="menu menu-horizontal px-1 gap-1">
+<!--NAV_ITEMS-->
+      </ul>
+    </div>
+    <div class="navbar-end gap-2 ml-auto">
+      <label class="swap swap-rotate btn btn-ghost btn-circle" title="Toggle light/dark">
+        <input type="checkbox" class="theme-controller" value="light" />
+        <svg class="swap-off h-5 w-5 fill-current" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
+          <path d="M21.64 13a1 1 0 0 0-1.27-.66 8.5 8.5 0 0 1-10.71-10.71 1 1 0 0 0-1.32-1.27A10 10 0 1 0 22 14.29a1 1 0 0 0-.36-1.29z"/>
+        </svg>
+        <svg class="swap-on h-5 w-5 fill-current" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
+          <path d="M5.64 17l-.71.71a1 1 0 0 0 1.41 1.41l.71-.71A1 1 0 0 0 5.64 17zM5 12a1 1 0 0 0-1-1H3a1 1 0 0 0 0 2h1a1 1 0 0 0 1-1zm7-7a1 1 0 0 0 1-1V3a1 1 0 0 0-2 0v1a1 1 0 0 0 1 1zM5.64 7.05a1 1 0 0 0 .7.29 1 1 0 0 0 .71-.29 1 1 0 0 0 0-1.41l-.71-.71a1 1 0 0 0-1.41 1.41zm12 .29a1 1 0 0 0 .7-.29l.71-.71a1 1 0 0 0-1.41-1.41l-.71.71a1 1 0 0 0 0 1.41 1 1 0 0 0 .71.29zM21 11h-1a1 1 0 0 0 0 2h1a1 1 0 0 0 0-2zm-9 8a1 1 0 0 0-1 1v1a1 1 0 0 0 2 0v-1a1 1 0 0 0-1-1zm6.36-2a1 1 0 0 0-1.41 1.41l.71.71a1 1 0 0 0 1.41-1.41zM12 6.5a5.5 5.5 0 1 0 5.5 5.5A5.51 5.51 0 0 0 12 6.5z"/>
+        </svg>
+      </label>
+      <div class="dropdown dropdown-end lg:hidden">
+        <label tabindex="0" class="btn btn-ghost btn-circle">
+          <svg xmlns="http://www.w3.org/2000/svg" class="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16" />
+          </svg>
+        </label>
+        <ul tabindex="0" class="menu menu-sm dropdown-content mt-3 z-[1] p-2 shadow bg-base-200 rounded-box w-52">
+<!--NAV_ITEMS-->
+        </ul>
+      </div>
+    </div>
+  </div>
+
+</header>