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>

patterns/header-centered.php

@@ -0,0 +1,32 @@
+<?php
+/**
+ * Title: Header - Centered
+ * Slug: wp-bootstrap/header-centered
+ * Categories: header
+ * Block Types: core/template-part/header
+ * Description: Centered header with site title above navigation.
+ *
+ * @package WPBootstrap
+ * @since 0.2.0
+ */
+?>
+<!-- wp:group {"align":"full","layout":{"type":"default"}} -->
+<div class="wp-block-group alignfull">
+	<!-- wp:group {"layout":{"type":"constrained"}} -->
+	<div class="wp-block-group">
+		<!-- wp:group {"align":"wide","style":{"spacing":{"padding":{"top":"var:preset|spacing|40","bottom":"var:preset|spacing|20"}}},"layout":{"type":"flex","orientation":"vertical","justifyContent":"center"}} -->
+		<div class="wp-block-group alignwide" style="padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--20)">
+			<!-- wp:site-title {"level":0,"textAlign":"center"} /-->
+			<!-- wp:site-tagline {"textAlign":"center","fontSize":"small"} /-->
+		</div>
+		<!-- /wp:group -->
+		<!-- wp:group {"align":"wide","style":{"spacing":{"padding":{"top":"var:preset|spacing|20","bottom":"var:preset|spacing|30"}}},"layout":{"type":"flex","flexWrap":"nowrap","justifyContent":"center"}} -->
+		<div class="wp-block-group alignwide" style="padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--30)">
+			<!-- wp:navigation {"overlayBackgroundColor":"base","overlayTextColor":"contrast","layout":{"type":"flex","justifyContent":"center","flexWrap":"wrap"}} /-->
+			<!-- wp:pattern {"slug":"wp-bootstrap/dark-mode-toggle"} /-->
+		</div>
+		<!-- /wp:group -->
+	</div>
+	<!-- /wp:group -->
+</div>
+<!-- /wp:group -->