feat: site restructure — layouts gallery, docs sections with inline demos

Navigation: Docs, Layouts, Lab (simplified from 6 items)

Layouts gallery: card grid showing all available page layouts
with live links to demo pages.

Docs restructure: 8 auto-generated sidebar sections
(Getting Started, Typography, Core, Content, Components,
Reference, Vault, Packs) with 20 new stub pages.
Each stub has inline HTML demos that ASW styles directly.

New Hugo layout template for layouts/ section.
Decap CMS nav updated.

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

site/content/docs/packs/hugo.md

@@ -0,0 +1,29 @@
+---
+title: "Hugo Pack"
+description: "Using ASW with Hugo — the theme, shortcodes, and configuration."
+type: docs
+weight: 52
+date: 2026-04-11
+tags: ["packs", "hugo"]
+ai-disclosure: "generated"
+ai-model: "claude-sonnet-4-6"
+ai-provider: "Anthropic"
+---
+
+The Hugo pack (`packs/hugo/`) is a complete Hugo theme built on ASW. It maps Hugo's Markdown pipeline to semantic HTML that ASW styles automatically. This documentation site is built with it.
+
+## Setup
+
+Symlink or copy `packs/hugo/` into your Hugo project's `themes/` directory, then set `theme = "asw-hugo"` in `hugo.toml`. Enable unsafe HTML rendering so that raw HTML blocks in Markdown pass through:
+
+```toml
+[markup.goldmark.renderer]
+  unsafe = true
+
+[markup.tableOfContents]
+  startLevel = 2
+  endLevel   = 3
+  ordered    = false
+```
+
+The pack provides layouts for `docs`, `blog`, and default page types. No additional configuration is required for basic use.