feat: add hallmark design skill

Anti-AI-slop design skill (greenfield pages, audits, redesigns, design
extraction from URLs/screenshots) -- installed and validated in an
earlier session, was sitting untracked. Full reference library:
components, macrostructures, themes, genres, verbs (audit/redesign).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

skills/hallmark/references/components/ft1-mast-headed.md

@@ -0,0 +1,13 @@
+
+### Ft1 · Mast-headed
+A wordmark and tagline anchor a single horizontal band. Two or three small links beside, address or licence below.
+*Use when:* the page has heavy content; the footer should be quiet and singular.
+*Don't confuse with:* Ft2 Inline-rule (which is even more reduced).
+
+```html
+<footer class="foot-mast">
+  <p class="wordmark">Studio Name</p>
+  <p class="tagline muted">Designs that don't look generated.</p>
+  <p class="links muted">Imprint · Privacy · Contact</p>
+</footer>
+```