Rename image fields and implement werk-in-detail gallery

- Rename image_main/image_secondary/image_logo/image_portrait to
  portret/extra_1/logo/extra_2 in pages, blueprints, and templates
- Add extra_2 image slot to home and CV (hidden on mobile)
- Wire werk-in-detail to real child pages instead of picsum placeholders
- Remove glightbox CDN dependency from werk-in-detail
- Add album blueprint, template, and grote-objecten album page

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

user/themes/natascha/blueprints/cv.yaml

@@ -13,11 +13,19 @@ form:
           type: tab
           title: Inhoud
           fields:
-            header.image_portrait:
+            header.portret:
               type: pagemediaselect
-              label: 'Portretfoto'
+              label: 'Portret (zichtbaar op mobiel)'
               preview_images: true
-            header.image_logo:
+            header.extra_1:
               type: pagemediaselect
-              label: 'Logo'
+              label: 'Extra foto (verborgen op mobiel)'
+              preview_images: true
+            header.logo:
+              type: pagemediaselect
+              label: 'Logo (zichtbaar op mobiel)'
+              preview_images: true
+            header.extra_2:
+              type: pagemediaselect
+              label: 'Extra foto rechts (verborgen op mobiel)'
               preview_images: true