{# Processing-history list — rendered to a string and emitted as the `history`
   panel's payload (kind="html"). #}
<ul class="history-list">
  {% for e in history_entries %}
  <li>
    <span class="history-ts">{{ e.timestamp }}</span>
    <span class="history-text">{{ e.text }}</span>
  </li>
  {% endfor %}
</ul>