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>

templates/page-hero.html

@@ -0,0 +1,14 @@
+<!-- wp:template-part {"slug":"header"} /-->
+
+<!-- wp:group {"tagName":"main","layout":{"type":"default"}} -->
+<main class="wp-block-group">
+<!-- wp:pattern {"slug":"wp-bootstrap/hero-cover"} /-->
+<!-- wp:group {"layout":{"type":"constrained"}} -->
+<div class="wp-block-group">
+<!-- wp:post-content {"layout":{"type":"constrained"}} /-->
+</div>
+<!-- /wp:group -->
+</main>
+<!-- /wp:group -->
+
+<!-- wp:template-part {"slug":"footer"} /-->