asw-v01: archive deferred content (packs, site, lab, legacy examples)

- 2.1: packs/ -> archive/packs/
- 2.2: site/ -> archive/site/
- 2.3: src/lab/ -> archive/lab/
- 2.4: examples/ -> archive/examples-legacy/ (SSI-based)

archive/site/layouts/partials/nav.html

@@ -0,0 +1,29 @@
+<nav>
+  <ul><li><a href="/"><strong>{{ .Site.Title }}</strong></a></li></ul>
+  <ul data-nav-links>
+    {{- range sort .Site.Data.nav.items "weight" }}
+    <li><a href="{{ .url }}"{{ if eq (relURL .url) $.RelPermalink }} aria-current="page"{{ end }}>{{ .name }}</a></li>
+    {{- end }}
+  </ul>
+  <button data-nav-toggle aria-label="Menu" hidden></button>
+  <button data-theme-toggle aria-label="Toggle theme"></button>
+</nav>
+<script>
+// Hamburger — toggle nav links on mobile
+(function(){
+  var btn = document.querySelector('[data-nav-toggle]');
+  var links = document.querySelector('[data-nav-links]');
+  if (!btn || !links) return;
+  // Show button only when JS is available
+  if (matchMedia('(max-width:767.98px)').matches) btn.hidden = false;
+  matchMedia('(max-width:767.98px)').addEventListener('change', function(e) {
+    btn.hidden = !e.matches;
+    if (!e.matches) links.removeAttribute('data-collapsed');
+  });
+  btn.addEventListener('click', function() {
+    var open = links.hasAttribute('data-collapsed');
+    if (open) links.removeAttribute('data-collapsed');
+    else links.setAttribute('data-collapsed', '');
+  });
+})();
+</script>