refactor: restructure repo into src/ site/ dist/ vendor/ packs/

Separate framework source from website:
- src/layers/ + src/main.css: CSS framework source (was assets/css/)
- site/: Hugo website (content/, layouts/, hugo.toml)
- dist/: built output (asw.css, asw.min.css)
- vendor/open-props/: vendored dependency with version tracking
- Hugo module mounts: dist/ → static, site runs from site/

Build: hugo --source site/ passes (105 pages).
npm run build produces dist/asw.css.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

site/layouts/console/single.html

@@ -0,0 +1,90 @@
+{{ define "header" }}
+  <header>
+    {{- if .Description -}}
+    <hgroup>
+      <h1>{{ .Title }}</h1>
+      <p>{{ .Description }}</p>
+    </hgroup>
+    {{- else -}}
+    <h1>{{ .Title }}</h1>
+    {{- end }}
+  </header>
+{{ end }}
+
+{{ define "content" }}
+  <section data-layout="console">
+
+    <nav aria-label="Documentation" data-nav="sidebar">
+      {{- $menu := index .Site.Menus "docs" -}}
+      {{- if $menu -}}
+        {{- range $menu -}}
+          {{- if .HasChildren -}}
+          <h3>{{ .Name }}</h3>
+          <ul>
+            {{- range .Children -}}
+            <li>
+              <a href="{{ .URL }}"
+                {{- if eq (relURL .URL) $.RelPermalink }} aria-current="page"{{ end -}}>
+                {{- .Name -}}
+              </a>
+            </li>
+            {{- end -}}
+          </ul>
+          {{- else -}}
+          <ul>
+            <li>
+              <a href="{{ .URL }}"
+                {{- if eq (relURL .URL) $.RelPermalink }} aria-current="page"{{ end -}}>
+                {{- .Name -}}
+              </a>
+            </li>
+          </ul>
+          {{- end -}}
+        {{- end -}}
+      {{- else -}}
+        {{- with .CurrentSection -}}
+        <h3>{{ .Title }}</h3>
+        <ul>
+          {{- range .RegularPages -}}
+          <li>
+            <a href="{{ .RelPermalink }}"
+               {{- if eq .RelPermalink $.RelPermalink }} aria-current="page"{{ end -}}>
+              {{- .LinkTitle -}}
+            </a>
+          </li>
+          {{- end -}}
+        </ul>
+        {{- end -}}
+      {{- end -}}
+    </nav>
+
+    <article>
+      {{ .Content }}
+
+      {{- if or .PrevInSection .NextInSection -}}
+      <footer data-role="prev-next">
+        {{- with .NextInSection -}}
+        <a href="{{ .RelPermalink }}" rel="prev">
+          <span aria-hidden="true">←</span> Previous
+          <span>{{ .LinkTitle }}</span>
+        </a>
+        {{- end -}}
+        {{- with .PrevInSection -}}
+        <a href="{{ .RelPermalink }}" rel="next">
+          Next <span aria-hidden="true">→</span>
+          <span>{{ .LinkTitle }}</span>
+        </a>
+        {{- end -}}
+      </footer>
+      {{- end -}}
+    </article>
+
+    {{- with .TableOfContents -}}
+    <aside data-toc>
+      <h3>On this page</h3>
+      {{ . }}
+    </aside>
+    {{- end -}}
+
+  </section>
+{{ end }}