Add Relays group (chat/file/message) + faded homepage dividers

New collapsible 'Relays' group in the sidebar (chat/file/message relay) that
expands to show its items and persists open state. Homepage gets a matching
Relays card group, and areas are now split by faded separator bars like the
sidebar. Relay pages are placeholder 'coming soon' stubs (/relays/{kind}).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

manager/templates/home.html

@@ -8,7 +8,8 @@
   .home-head p { color: var(--muted); font-size: 14px; }
 
   .tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 16px; }
-  .tiles + .tiles { margin-top: 32px; }   /* vertical buffer between areas */
+  /* faded bar between areas, like the sidebar separators */
+  .tiles + .tiles { margin-top: 28px; padding-top: 28px; border-top: 1px solid var(--border); }
   .tile {
     display: flex; flex-direction: column; gap: 8px;
     background: var(--card); border: 1px solid var(--border); border-radius: 12px;
@@ -58,6 +59,25 @@
   </a>
 </div>
 
+<!-- Area: relays -->
+<div class="tiles">
+  <a class="tile" href="/relays/chat">
+    <span class="t-ico">💬</span>
+    <span class="t-title">Chat relay</span>
+    <span class="t-desc">Relay chat messages between connections.</span>
+  </a>
+  <a class="tile" href="/relays/file">
+    <span class="t-ico">📁</span>
+    <span class="t-title">File relay</span>
+    <span class="t-desc">Relay files between connections.</span>
+  </a>
+  <a class="tile" href="/relays/message">
+    <span class="t-ico">✉️</span>
+    <span class="t-title">Message relay</span>
+    <span class="t-desc">Relay messages between connections.</span>
+  </a>
+</div>
+
 <!-- Area 2: manage -->
 <div class="tiles">
   <a class="tile" href="/network">