Invert image order in beforeafter block preview

- Image "before" now displays on top (left side, clipped at 50%)
- Image "after" displays below (visible on right side)
- Update text block to support bullet lists
- Add heading fieldset to report blueprint

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

site/plugins/beforeafter/blueprints/blocks/beforeafter.yml

@@ -9,7 +9,8 @@ fields:
     layout: cards
     query: page.images
     uploads: false
-    help: Image affichée à gauche / dessous
+    help: Image affichée à gauche / dessus
+    width: 1/2
   imageAfter:
     label: Image "Après"
     type: files
@@ -17,19 +18,9 @@ fields:
     layout: cards
     query: page.images
     uploads: false
-    help: Image affichée à droite / dessus
+    help: Image affichée à droite / dessous
+    width: 1/2
   caption:
     label: Légende
     type: text
     help: Légende commune aux deux images
-  text:
-    label: Texte accompagnant
-    type: writer
-    marks:
-      - bold
-      - italic
-      - link
-    nodes:
-      - bulletList
-      - orderedList
-      - paragraph