version 5.1.8

- fix: matrix/sms_voipms notifications blocked the event loop on timeout;
  make send_notification async, dispatch all channel drivers as non-blocking
  tasks (asyncio.to_thread for sync drivers, asyncio.wait_for for async);
  update all call sites to fire-and-forget via create_task
- feat: add /about page with version, runtime, uptime counter, and repo link
- fix: hbc_mini plugin data format now matches full hbc client so Host
  Overview displays memory, disk, and network metrics correctly

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

hbd/server/templates/nav.html

@@ -9,6 +9,7 @@
     {% if current_user and current_user.admin %}
     <a href="/settings"{% if active_page == "settings" %} class="active"{% endif %}>Settings</a>
     {% endif %}
+    <a href="/about"{% if active_page == "about" %} class="active"{% endif %}>About</a>
   </div>
   <div class="nav-clock" title="Click for full-screen clock">
     <canvas id="swiss-clock" width="44" height="44"></canvas>