Initial theme scaffolding (v0.0.1)

- Bootstrap 5 CSS/JS integration via Yarn (served locally)
- Dart Sass build pipeline with PostCSS, Autoprefixer, cssnano
- Twig 3.0 via Composer with PSR-4 autoloading
- FSE block theme templates (index, home, single, page, archive, search, 404)
- Template parts (header, footer) and block patterns
- theme.json with Bootstrap 5-aligned design tokens
- Gitea CI/CD workflow for automated release packages
- WordPress i18n support (en_US base, de_CH translation)

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

patterns/hidden-404.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * Title: 404
+ * Slug: wp-bootstrap/hidden-404
+ * Inserter: no
+ *
+ * @package WPBootstrap
+ * @since 0.0.1
+ */
+?>
+<!-- wp:group {"layout":{"type":"constrained"}} -->
+<div class="wp-block-group">
+	<!-- wp:heading {"level":1,"align":"wide"} -->
+	<h1 class="alignwide"><?php esc_html_e( 'Page not found', 'wp-bootstrap' ); ?></h1>
+	<!-- /wp:heading -->
+
+	<!-- wp:paragraph -->
+	<p><?php esc_html_e( 'The page you are looking for does not exist, or it has been moved. Please try searching using the form below.', 'wp-bootstrap' ); ?></p>
+	<!-- /wp:paragraph -->
+
+	<!-- wp:pattern {"slug":"wp-bootstrap/hidden-search"} /-->
+</div>
+<!-- /wp:group -->