Autor-Seiten: /authors/<slug>/ (rundes Bild, Name, Bio, zentriert) + Byline-Link

- layouts/authors/single.html rendert die Autor-Seite zentriert
- Byline in single.html + index.html verlinkt den Autornamen zu /authors/<urlize name>/
  (nur wenn die Seite existiert)
- CMS-Profil-Speichern schreibt content/authors/<slug>.md (aus Name/Bio/Avatar)
  + data/authors.json und baut public neu → Seite & Links sofort live
- Autor-Seiten aus dem Inhalts-Editor ausgeblendet (über „Profil" verwaltet)
- custom.css: .author-page / -photo / -name / -bio + Byline-Link-Stil

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

layouts/index.html

@@ -15,6 +15,7 @@
         {{ $section := "" }}
         {{ with .Parent }}{{ $section = path.Base .RelPermalink }}{{ end }}
         {{ $author := .Params.author | default site.Params.author.name }}
+        {{ $authorPage := cond (ne $author "") (site.GetPage (printf "/authors/%s" (urlize $author))) false }}
         {{ $cover := .Params.cover_image }}
         {{/* Layout: explicit `layout:` in front matter, else derive:
              - cover_image present → image
@@ -42,7 +43,10 @@
                 <p class="journal-summary">{{ . }}</p>
               {{ end }}
               <p class="journal-byline">
-                {{- with $author -}}<span class="journal-author">{{ . }}</span>{{- end -}}
+                {{- with $author -}}
+                  {{- if $authorPage -}}<a class="journal-author" href="{{ $authorPage.RelPermalink }}">{{ . }}</a>
+                  {{- else -}}<span class="journal-author">{{ . }}</span>{{- end -}}
+                {{- end -}}
                 {{- if and $author .Date -}}, {{ end -}}
                 <time class="journal-date" datetime="{{ .Date.Format "2006-01-02" }}">{{ .Date.Format "02.01.2006" }}</time>
               </p>