Add show/hide Link + QR toggles for every SimpleX link (default hidden)

Reusable link box (Jinja macro in _macros.html + shared JS/CSS/QR lib in
base.html): a 'Link' button toggles the URL (with copy) and a 'QR' button toggles
a lazily-rendered QR of the same link — both hidden by default. Applied to the
profile address, profile groups & channels, and the profile cards on the list
pages. Centralize robustCopy in base.html; drop the per-page duplicates and the
old async group-link fetch (groups now use their known link).

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

manager/templates/list.html

@@ -1,4 +1,5 @@
 {% extends "base.html" %}
+{% import "_macros.html" as ui %}
 {% block title %}{{ 'Business Groups' if tab == 'businesses' else tab | title }} — SimpleX Manager{% endblock %}
 
 {% block head %}
@@ -95,11 +96,7 @@
       </div>
     </div>
     {% 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 }}')"><i class="fa-solid fa-copy"></i></button>
-      <a class="addr-link" href="{{ p.address }}" target="_blank" rel="noopener">{{ p.address }}</a>
-    </div>
+    <div onclick="event.stopPropagation()" style="margin-top:10px;">{{ ui.linkbox(p.address, 'p' ~ p.id) }}</div>
     {% endif %}
   </div>
   {% endfor %}
@@ -344,27 +341,7 @@ function onAvatarChange(input) {
   reader.readAsDataURL(file);
 }
 
-// Clipboard that also works over plain-HTTP LAN (navigator.clipboard needs a secure context).
-function robustCopy(text) {
-  if (navigator.clipboard && window.isSecureContext) {
-    return navigator.clipboard.writeText(text).catch(() => fallbackCopy(text));
-  }
-  return Promise.resolve(fallbackCopy(text));
-}
-function fallbackCopy(text) {
-  const ta = document.createElement('textarea');
-  ta.value = text; ta.style.position = 'fixed'; ta.style.opacity = '0';
-  document.body.appendChild(ta); ta.focus(); ta.select();
-  try { document.execCommand('copy'); } catch (e) {}
-  document.body.removeChild(ta);
-}
-function copyAddr(ev, btn, addr) {
-  ev.stopPropagation();
-  robustCopy(addr).then(() => {
-    btn.innerHTML = '<i class="fa-solid fa-check"></i>';
-    setTimeout(() => btn.innerHTML = '<i class="fa-solid fa-copy"></i>', 1500);
-  });
-}
+// robustCopy and the SimpleX link box (sx*) live in base.html (shared).
 
 {% if tab == 'bots' %}
 function onTypeChange() {