Replace v1 with v2 codebase

Full rewrite: swap out the v1 framework (src/, controllers/, views/,
twig/, sass/, skeleton/) for the working v2 codebase from phpproject
(App/, novaconium/, public/).

App/pages/blog/_layout/layout.twig

@@ -0,0 +1,15 @@
+{% extends '_layout/layout.twig' %}
+
+{% import '_layout/icons.twig' as icons %}
+
+{% block content %}
+    <div class="blog-layout">
+        <aside>
+            <p>This sidebar exists because <code>App/pages/blog/_layout/layout.twig</code> overrides the site-wide root layout for everything under <code>/blog</code> — the nearest <code>_layout/layout.twig</code> wins, so a subtree can look different without touching the pages themselves.</p>
+            <p><a class="icon-link" href="/admin/docs/layouts">{{ icons.book() }}Layouts docs</a></p>
+        </aside>
+        <article>
+            {% block blog_content %}{% endblock %}
+        </article>
+    </div>
+{% endblock %}