{#-
  mermaid — render a sequence/flow diagram from a raw .mmd file under blog/diagrams/.
  Loading from a file (rather than a shortcode body) keeps the diagram source out of the
  Markdown pipeline, so arrows like -->> are never mangled. Rendered client-side by the
  pinned mermaid bundle (loaded from a CDN with Subresource Integrity) wired up in base.html.

  Params:
    path    – file name under blog/diagrams/, e.g. "async-stream.mmd" (required)
    caption – optional caption shown under the diagram
-#}
<figure class="diagram">
<pre class="mermaid">
{{ load_data(path="diagrams/" ~ path, format="plain") | trim }}
</pre>
{%- if caption %}
<figcaption>{{ caption }}</figcaption>
{%- endif %}
</figure>