feat(web): redesign skills catalog and registry browser

Group the 24 built-in skills by purpose on /skills and render each skill's real SKILL.md on its page, on the docs reading layout and in Cmd+K search. Replace the registry card grid with a one-line-per-skill list, and open registry skills on a noindex page (/skills/registry/?skill=owner/repo/name) that shows the install command and the skill's SKILL.md, rendered without raw HTML. Back to the list keeps search, filter, and scroll.

Redeploy the site when a skills/*/SKILL.md changes. SEO: same titles, descriptions, canonicals, and JSON-LD on existing skills pages; no page loses text or links.

Author: codeaholicguy

.github/workflows/deploy-web.yml

@@ -6,6 +6,7 @@ on:
       - main
     paths:
       - 'web/**'
+      - 'skills/*/SKILL.md'
       - '.github/workflows/deploy-web.yml'
   workflow_dispatch: