Add sub-component support via self-referential device hierarchy

templates/device_list.html

@@ -66,7 +66,14 @@
             data-location="{{ d.location or '' }}"
             data-fill="{{ fill_state }}"
             data-name="{{ d.name|lower }}">
-          <td data-label="Device"><a href="{{ url_for('device_detail', device_id=d.id) }}"><strong>{{ d.name }}</strong></a></td>
+          <td data-label="Device">
+            <a href="{{ url_for('device_detail', device_id=d.id) }}"><strong>{{ d.name }}</strong></a>
+            {% if d.parent %}
+            <br><small class="text-muted">↳ <a href="{{ url_for('device_detail', device_id=d.parent.id) }}">{{ d.parent.name }}</a></small>
+            {% elif d.has_children() %}
+            <br><small class="text-muted">{{ d.children|length }} sub-component{{ 's' if d.children|length != 1 }}</small>
+            {% endif %}
+          </td>
           <td data-label="Type">{{ d.device_type or '—' }}</td>
           <td data-label="Size">{{ d.battery_size or '—' }}</td>
           <td data-label="Location">{{ d.location or '—' }}</td>