[people] Port Ludo profile from vault to garden

- Adapted internal vault/people/ludo.md to public introduction at
  content/about/ludo.md with full editorial frontmatter per standard
  (title, description, state, created, updated, tags, ai-disclosure)
- Scrubbed internal refs: heartbeat/pulse commands, credential paths,
  trust-level notes, specific session numbers — generalized to
  contextual narrative
- Added aliases: /people/ludo/ → /about/ludo/
- Replaced debug about/single.html template with proper rendering
- Removed stale people/ludo.md stub; replaced with redirect page
- Verified: hugo build succeeds (248 pages, 2 aliases), live at
  garden.trentuna.com/about/ludo/ (HTTP 200)

Pilot 5 — people profile → garden routing.

layouts/about/single.html

@@ -0,0 +1,21 @@
+{{ define "main" }}
+<article>
+  <header>
+    <h1>{{ .Title }}</h1>
+
+    {{- with .Description }}
+    <p data-text="dim">{{ . }}</p>
+    {{- end }}
+
+    {{- with .GetTerms "tags" }}
+    <nav data-role="tag-cloud" aria-label="Tags">
+      {{- range . }}
+      <a href="{{ .Permalink }}" data-tag="{{ .Name }}">{{ .Name }}</a>
+      {{- end }}
+    </nav>
+    {{- end }}
+  </header>
+
+  {{ .Content }}
+</article>
+{{ end }}