feat: legacy import — packs, examples, lab, themes, docs, lineage

Import from agentic-semantic-web/ into restructured repo:
- 7 packs (apache, caddy, flask, hugo, nginx, pandoc, python)
- shared error pages (403-503)
- 17 lab experiments (boilerplate, charts, misc)
- 31 example pages (charts, components, content, layout, vault)
- 2 themes (garden, trentuna stub)
- 4 docs (llms.txt, vocabulary, philosophy, agent-directive)
- lineage.md (Pico/Open Props/Charts.css history)
- Hugo mounts for lab/ and examples/

All agentic.css references updated to asw.css.

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

packs/hugo/layouts/shortcodes/callout.html

@@ -0,0 +1,16 @@
+{{- /*
+  callout shortcode — wraps content in an ASW callout block.
+  
+  Usage:
+    {{< callout note >}}
+    Content here. Markdown is rendered.
+    {{< /callout >}}
+  
+  First positional param: callout type.
+  Valid types: note, warning, tip, info (maps to ASW data-callout attribute).
+  Default: note
+*/ -}}
+{{- $type := .Get 0 | default "note" -}}
+<aside data-callout="{{ $type }}">
+  {{ .Inner | markdownify }}
+</aside>