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/_default/_markup/render-footnotes.html

@@ -0,0 +1,13 @@
+{{- /* render-footnotes.html
+     Replace Hugo's default <div class="footnotes"> with ASW-semantic markup.
+     Hugo v0.123.0+ render hook for the footnote block.
+     Ref: https://gohugo.io/render-hooks/footnotes/
+*/ -}}
+<footer data-role="footnotes">
+  <hr>
+  <ol>
+    {{- range .Items }}
+    <li id="{{ .ID }}">{{ .Content }}{{ .Return }}</li>
+    {{- end }}
+  </ol>
+</footer>