Upgrade page headers to lt-page-header/lt-page-title across all pages

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

templates/links.html

@@ -3,13 +3,14 @@
 
 {% block content %}
 
-<div class="g-page-header">
-  <h1 class="g-page-title">Link Debug</h1>
-  <p class="g-page-sub">
-    Per-interface stats: speed, duplex, SFP optical levels, TX/RX rates, errors, and carrier changes.
-    Data collected via Prometheus node_exporter + SSH ethtool (servers) and UniFi API (switches) every poll cycle.
-    <span id="links-updated" style="margin-left:10px; color:var(--text-muted); font-size:.85em;"></span>
-  </p>
+<div class="lt-page-header">
+  <div>
+    <h1 class="lt-page-title">Link Debug</h1>
+    <p class="g-page-sub" style="margin-top:4px">
+      Per-interface stats: speed, duplex, SFP optical levels, TX/RX rates, errors, and carrier changes.
+      <span id="links-updated" style="margin-left:8px"></span>
+    </p>
+  </div>
 </div>
 
 <div id="links-container">