Wave 2: content fixes, deploy pipeline, layout refinements

- dorveille.md: add ai-model/ai-provider frontmatter, restore mark tags
- hugo.toml: goldmark.renderer.unsafe=true (mark/abbr support)
- layouts: extract nav partial, fix JSON-LD, simplify list/index
- deploy.sh: push-to-render build script (webhook-receiver triggers it)
- render-footnotes.html: class-free footnote hook (staged for Hugo upgrade)

layouts/partials/nav.html

@@ -0,0 +1,7 @@
+<nav>
+  <ul><li><a href="/"><strong>{{ .Site.Title }}</strong></a></li></ul>
+  <ul>
+    <li><a href="/docs/">Docs</a></li>
+    <li><a href="/examples/">Examples</a></li>
+  </ul>
+</nav>