ui: Headings kleiner + Library als Archiv-Zwilling (Sidebar weg)

- section-title 2.6→1.9rem max, 800→700; single-header h1 3→2.2rem max, 800→700;
  single-summary 1.4→1.2rem. Ruhiger, redaktioneller, site-weit.
- Library raus aus der zweispaltigen Sonderform: Übersicht = .atlas (gruppiert,
  wie Archiv-Root), Eintrag = .single (wie Essay) mit Quellen + Fuss
  (Gruppe · weitere Einträge · bearbeiten). library-nav-Partial entfernt.
- Voll CI-konform: Archiv und Library teilen jetzt dasselbe Gerüst.

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

layouts/library/single.html

@@ -1,33 +1,35 @@
 {{ define "main" }}
-  <header class="section-header">
-    <p class="section-rubric">{{ with .Params.group }}{{ . }}{{ else }}Library{{ end }}</p>
-    <h1 class="section-title">{{ .Title }}</h1>
-    {{ with .Params.summary }}<p class="section-description">{{ . }}</p>{{ end }}
-  </header>
+  <article class="single">
+    <header class="single-header">
+      <h1>{{ .Title }}</h1>
+      {{ with .Params.summary }}<p class="single-summary">{{ . }}</p>{{ end }}
+    </header>
 
-  <div class="wiki">
-    <aside class="wiki-side">{{ partial "library-nav.html" . }}</aside>
+    {{ $hasToC := .Params.toc | default false }}
+    {{ $headers := findRE "<h[2-6]" .Content }}
+    {{ if and $hasToC (ge (len $headers) 2) }}
+      <nav class="toc">
+        <strong>Inhalt</strong>
+        <div class="toc-content">{{ .TableOfContents }}</div>
+      </nav>
+    {{ end }}
 
-    <div class="wiki-page">
-      {{ $hasToC := .Params.toc | default false }}
-      {{ $headers := findRE "<h[2-6]" .Content }}
-      {{ if and $hasToC (ge (len $headers) 2) }}
-        <nav class="toc">
-          <strong>Inhalt</strong>
-          <div class="toc-content">{{ .TableOfContents }}</div>
-        </nav>
-      {{ end }}
-
-      <div class="single-content wiki-content">
-        {{ .Content }}
-      </div>
-
-      <div class="wiki-foot">
-        {{ if .Lastmod }}<span>Zuletzt bearbeitet am {{ .Lastmod.Format "02.01.2006" }}</span>{{ end }}
-        {{ with .File }}
-          <a href="{{ site.Params.repoURL }}/_edit/branch/main/content/{{ .Path }}" rel="nofollow">bearbeiten ↗</a>
-        {{ end }}
-      </div>
+    <div class="single-content">
+      {{ .Content }}
     </div>
-  </div>
+
+    {{/* Fuss: Gruppe + weitere Einträge derselben Gruppe + bearbeiten. */}}
+    {{ $g := .Params.group | default "Allgemein" }}
+    {{ $siblings := where (where site.RegularPages "Section" "library") "Params.group" (.Params.group) }}
+    <div class="entry-foot">
+      <span class="entry-more">
+        <strong>{{ $g }}</strong>
+        {{ $others := slice }}
+        {{ range $siblings }}{{ if ne .RelPermalink $.RelPermalink }}{{ $others = $others | append . }}{{ end }}{{ end }}
+        {{ with $others }} · {{ range $i, $p := . }}{{ if $i }} · {{ end }}<a href="{{ $p.RelPermalink }}">{{ $p.LinkTitle }}</a>{{ end }}{{ end }}
+      </span>
+      {{ if .Lastmod }}<span>Zuletzt bearbeitet am {{ .Lastmod.Format "02.01.2006" }}</span>{{ end }}
+      {{ with .File }}<a href="{{ site.Params.repoURL }}/_edit/branch/main/content/{{ .Path }}" rel="nofollow">bearbeiten ↗</a>{{ end }}
+    </div>
+  </article>
 {{ end }}