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/content/notes/wikilinks.md

@@ -0,0 +1,26 @@
+---
+title: "Wikilinks"
+description: "Internal knowledge-graph links styled as dotted underlines."
+section: notes
+prev-url: "tasks/"
+prev-title: "Tasks"
+next-url: "status/"
+next-title: "Status"
+type: notes
+date: 2026-04-09
+tags: ["notes", "wikilinks", "reference"]
+ai-disclosure: "generated"
+ai-model: "claude-sonnet-4-5"
+ai-provider: "Anthropic"
+
+---
+
+## Overview
+
+Use `data-wikilink` on anchor tags to mark links as internal knowledge-graph references.
+
+```html
+<a href="/notes/tasks/" data-wikilink>Tasks</a>
+```
+
+Renders with a dotted underline distinguishing it from a regular hyperlink.