v0.2.0 - Design Editor: templates, patterns, header/footer variations

Full Design Editor compatibility with custom block categories, page templates,
header/footer variations, and navigation styles. Both FSE (admin) and Twig
(frontend) sides kept in sync.

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

views/pages/page-sidebar.html.twig

@@ -0,0 +1,24 @@
+{% extends 'base.html.twig' %}
+
+{% block content %}
+<div class="container">
+    <div class="row">
+        <div class="col-lg-8">
+            <article>
+                <h1 class="mb-4">{{ post.title }}</h1>
+                {% if post.thumbnail %}
+                    <img src="{{ post.thumbnail }}" class="img-fluid rounded mb-4"
+                         alt="{{ post.title|e('html_attr') }}">
+                {% endif %}
+
+                <div class="post-content">
+                    {{ post.content|raw }}
+                </div>
+            </article>
+        </div>
+        <div class="col-lg-4">
+            {% include 'partials/sidebar.html.twig' %}
+        </div>
+    </div>
+</div>
+{% endblock %}