{# 🔭 track_history timeline subsection (ARG-161). Rendered inside
   _detail_signals.html when `item.related_history` is non-empty. #}
{% if item.related_history %}
<div class="signals-history">
  <h3 class="signals-subsection__label">최근 변화</h3>
  <ol class="signals-history__list">
    {% for h in item.related_history %}
    <li class="signals-history__entry">
      <a class="signals-history__tech" href="/item/{{ h.tech_id }}">{{ h.tech_title }}</a>
      <span class="signals-history__delta">
        <span class="signals-history__from">{{ h.changed_from }}</span>
        <span class="signals-history__arrow" aria-hidden="true">→</span>
        <span class="signals-history__to">{{ h.changed_to }}</span>
      </span>
      <time class="signals-history__time"
            datetime="{{ h.changed_at.isoformat() }}">{{ h.changed_at.strftime('%Y-%m-%d') }}</time>
    </li>
    {% endfor %}
  </ol>
</div>
{% endif %}