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/index.html

@@ -1,13 +1,7 @@
 {{ define "title" }}{{ .Site.Title }}{{ end }}
 
 {{ define "main" }}
-  <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>
+  {{ partial "nav.html" . }}
 
   <main>
     <article data-layout="prose">