Cleanup: strip redundant inline styles, add CSS classes

- Remove style="margin-top:4px" from .g-page-sub in all three secondary
  pages (the value is already defined in .g-page-sub rule in style.css)
- suppressions.html: replace inline style="padding:12px 14px" with TDS
  lt-section-body class
- index.html topology legend: replace inline dashed-border style with
  .topo-legend-item--offrack modifier class in style.css

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

templates/index.html

@@ -302,7 +302,7 @@
       <div class="topo-legend-item"><span class="topo-legend-line-wan"></span> WAN / uplink</div>
       <div class="topo-legend-item"><span class="topo-legend-line-10g"></span> 10G SFP+ (Ceph / VLAN90)</div>
       <div class="topo-legend-item"><span class="topo-legend-line-1g"></span> 1G DHCP (mgmt)</div>
-      <div class="topo-legend-item" style="border:1px dashed var(--border-color); padding:1px 5px; font-size:.56em; color:var(--text-muted);">dashed border = off-rack</div>
+      <div class="topo-legend-item topo-legend-item--offrack">dashed border = off-rack</div>
     </div>
 
   </div><!-- /topo-v2 -->

templates/inspector.html

@@ -6,7 +6,7 @@
 <div class="lt-page-header">
   <div>
     <h1 class="lt-page-title">Network Inspector</h1>
-    <p class="g-page-sub" style="margin-top:4px">
+    <p class="g-page-sub">
       Visual switch chassis diagrams. Click a port to see detailed stats and LLDP path debug.
       <span id="inspector-updated" style="margin-left:8px"></span>
     </p>

templates/links.html

@@ -6,7 +6,7 @@
 <div class="lt-page-header">
   <div>
     <h1 class="lt-page-title">Link Debug</h1>
-    <p class="g-page-sub" style="margin-top:4px">
+    <p class="g-page-sub">
       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>

templates/suppressions.html

@@ -6,7 +6,7 @@
 <div class="lt-page-header">
   <div>
     <h1 class="lt-page-title">Alert Suppressions</h1>
-    <p class="g-page-sub" style="margin-top:4px">Manage maintenance windows and per-target alert suppression rules.</p>
+    <p class="g-page-sub">Manage maintenance windows and per-target alert suppression rules.</p>
   </div>
 </div>
 
@@ -188,7 +188,7 @@
     <span class="lt-frame-bl">&#x255A;</span>
     <span class="lt-frame-br">&#x255D;</span>
     <div class="lt-section-header">Host &amp; Interface Reference</div>
-    <div style="padding:12px 14px">
+    <div class="lt-section-body">
       <div class="targets-grid">
         {% for name, host in snapshot.hosts.items() %}
         <div class="target-card">