Back up unsaved editor work locally, structure the settings, fix archive accessibility

- The editor keeps unsaved changes in the browser and offers them
  after a crash, a closed tab or an expired session. No timed save on
  the server: every save is a full revision.
- The save status stays visible in narrow windows.
- Settings get a sticky section bar, two folded groups and a save bar
  that stays in view.
- The admin post list fetches terms and images once, not per post.
- Archive post titles are second-level headings, the archive head
  keeps full text contrast, the skip link sits above a sticky header,
  a linked image without alternative text names its link.
- The editor check starts through the dev router like the others.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

src/Content/MediaLibrary.php

@@ -130,7 +130,8 @@ final class MediaLibrary
             'SELECT * FROM media WHERE id IN ('.implode(',', array_fill(0, count($ids), '?')).')',
             $ids,
         ) as $row) {
-            $found[$row['id']] = $this->present($row);
+            // Auch für find(): Wer die Bilder einer Liste vorab holt, erspart jede Einzelabfrage danach.
+            $found[$row['id']] = $this->gemerkt[$row['id']] = $this->present($row);
         }
 
         return $found;

src/Content/PostRepository.php

@@ -313,6 +313,40 @@ final class PostRepository
     }
 
     /** Term names of one page, as the comma separated list the metadata form edits. */
+    /**
+     * Kategorien und Schlagwörter mehrerer Beiträge in einer Abfrage, als Text je Beitrag.
+     *
+     * Die Liste der Verwaltung fragte vorher für jeden Beitrag einzeln nach: zwanzig Beiträge,
+     * vierzig Abfragen.
+     *
+     * @param list<string> $pageIds
+     *
+     * @return array<string, array{category: string, tag: string}>
+     */
+    public function namesForMany(array $pageIds): array
+    {
+        $names = [];
+        foreach ($this->termsForMany($pageIds) as $id => $terms) {
+            $names[$id] = [
+                'category' => implode(', ', array_column($terms['category'], 'name')),
+                'tag' => implode(', ', array_column($terms['tag'], 'name')),
+            ];
+        }
+
+        return $names;
+    }
+
+    /**
+     * Holt die Bilder einer Liste in einer Abfrage, damit die Vorlage sie danach einzeln findet,
+     * ohne je Zeile die Datenbank zu fragen.
+     *
+     * @param list<string|null> $mediaIds
+     */
+    public function preloadImages(array $mediaIds): void
+    {
+        $this->media->findMany(array_map('strval', array_filter($mediaIds)));
+    }
+
     public function namesFor(string $pageId): array
     {
         $terms = $this->termsFor($pageId);