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/tasks.md

@@ -0,0 +1,38 @@
+---
+title: "Tasks"
+description: "Render task lists with semantic state: done, wip, blocked, todo."
+section: notes
+prev-url: ""
+prev-title: ""
+next-url: "wikilinks/"
+next-title: "Wikilinks"
+type: notes
+date: 2026-04-09
+tags: ["notes", "tasks", "reference"]
+ai-disclosure: "generated"
+ai-model: "claude-sonnet-4-5"
+ai-provider: "Anthropic"
+
+---
+
+## Overview
+
+Use `data-task` on list items to convey task state without CSS classes.
+
+```html
+<ul>
+  <li data-task="done">Completed item</li>
+  <li data-task="wip">Work in progress</li>
+  <li data-task="blocked">Blocked item</li>
+  <li data-task="todo">Not started</li>
+</ul>
+```
+
+## States
+
+| Value | Meaning |
+|-------|---------|
+| `done` | Completed — green check |
+| `wip` | In progress — amber |
+| `blocked` | Blocked — red |
+| `todo` | Not started — muted |