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>

themes/natascha/templates/album.html.twig

@@ -0,0 +1,26 @@
+{% extends 'partials/base.html.twig' %}
+{% block extra_css %}
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/glightbox/dist/css/glightbox.min.css">
+{% endblock %}
+{% block extra_js %}
+<script src="https://cdn.jsdelivr.net/npm/glightbox/dist/js/glightbox.min.js" defer></script>
+{% endblock %}
+{% block content %}
+<div class="row mb-3">
+    <div class="col-12 col-lg-8 offset-lg-2">
+        <h1 class="funky-font main-header text-center">{{ page.title }}</h1>
+        {{ content|raw }}
+    </div>
+</div>
+<div class="row g-3">
+    {% for name, img in page.media.images %}
+    <div class="col-6 col-md-4 col-lg-3">
+        <a href="{{ img.url }}" class="glightbox gallery-item" data-gallery="{{ page.slug }}">
+            <div class="gallery-thumb">
+                <img src="{{ img.url }}" loading="lazy" alt="{{ page.title }}">
+            </div>
+        </a>
+    </div>
+    {% endfor %}
+</div>
+{% endblock %}