Site: the devlog, the blog's roro9stack posts in the site's style; Devlog replaces Blog in the navigation

Seven posts imported into site/content/devlog/ with their text unchanged,
links between them pointing to /devlog/, and shortcodes (sign, cast, steps,
asides, folded sections, diagrams, captions) restyled in the site's palette.
The 17 inline SVG diagrams carried <style> blocks and style attributes the
site's Content-Security-Policy refuses: their rules moved to
devlog-diagrams.css, and a diagram's minimum width is a class. An Atom feed
at /devlog/atom.xml.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

site/templates/shortcodes/sign.html

@@ -0,0 +1,5 @@
+{#- A big "days since…" sign: {{ sign(label="…", note="…", count="0", tone="red") }}. The same markup as the post header's -#}
+<div class="sign{% if tone %} {{ tone }}{% endif %}" role="img" aria-label="{{ label }}: {{ count }}">
+  <div class="label">{{ label }}<small>{{ note }}</small></div>
+  <div class="count">{{ count }}</div>
+</div>