feat(web): real /about and /docs pages (unique crawlable content)

Addresses the top cross-engine AEO finding — every route previously served
the homepage SPA. /about and /docs are now distinct routes with their own
server-rendered content and titles.

- /about: substantive about page (what LogicSRC is, the standards surface,
  CommandBoard.run reference impl, GitHub, hire-us) — derived from public
  positioning, no fabricated team.
- /docs + /docs/[slug]: render the repo's docs/*.md (curated public set) via
  marked, statically generated at build (no runtime fs dependency).
- Drop about/docs from the catch-all; add doc URLs to the sitemap.

Verified in a running build: /about and /docs serve unique content with
distinct titles; /docs/[slug] renders each markdown doc.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/logicsrc-web/package.json

@@ -14,6 +14,7 @@
   "dependencies": {
     "@profullstack/autoblog": "github:profullstack/autoblog#75e54af",
     "@supabase/supabase-js": "^2.105.4",
+    "marked": "^18.0.5",
     "next": "16.2.6",
     "react": "19.2.0",
     "react-dom": "19.2.0"