UI: Font Awesome icons, Material touches, 3-line collapse button

Swap all emoji icons for Font Awesome (sidebar, homepage tiles, profile/chat/
list/settings/relay actions); add Roboto font + card elevation hover for a
Material feel. Replace the bottom 'Collapse' pill with a 3-line (fa-bars) toggle
in the sidebar header; remove the old collapse pill CSS/JS. Copy buttons toggle
FA check/copy via innerHTML. Plain text status (✓/✗) and back arrows kept.

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

manager/templates/list.html

@@ -89,7 +89,7 @@
     {% if p.address %}
     <div class="addr-row" onclick="event.stopPropagation()">
       <button class="btn btn-ghost copy-btn" title="Copy address"
-              onclick="copyAddr(event, this, '{{ p.address | e }}')">📋</button>
+              onclick="copyAddr(event, this, '{{ p.address | e }}')"><i class="fa-solid fa-copy"></i></button>
       <a class="addr-link" href="{{ p.address }}" target="_blank" rel="noopener">{{ p.address }}</a>
     </div>
     {% endif %}
@@ -283,8 +283,8 @@ function onAvatarChange(input) {
 function copyAddr(ev, btn, addr) {
   ev.stopPropagation();
   navigator.clipboard.writeText(addr).then(() => {
-    btn.textContent = '✓';
-    setTimeout(() => btn.textContent = '📋', 1500);
+    btn.innerHTML = '<i class="fa-solid fa-check"></i>';
+    setTimeout(() => btn.innerHTML = '<i class="fa-solid fa-copy"></i>', 1500);
   });
 }