diff -r be944660c56a -r 3d72ae0968f4 wp/wp-admin/site-editor.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-admin/site-editor.php	Tue Sep 27 16:37:53 2022 +0200
@@ -0,0 +1,150 @@
+<?php
+/**
+ * Site Editor administration screen.
+ *
+ * @package WordPress
+ * @subpackage Administration
+ */
+
+global $post, $editor_styles;
+
+/** WordPress Administration Bootstrap */
+require_once __DIR__ . '/admin.php';
+
+if ( ! current_user_can( 'edit_theme_options' ) ) {
+	wp_die(
+		'<h1>' . __( 'You need a higher level of permission.' ) . '</h1>' .
+		'<p>' . __( 'Sorry, you are not allowed to edit theme options on this site.' ) . '</p>',
+		403
+	);
+}
+
+if ( ! wp_is_block_theme() ) {
+	wp_die( __( 'The theme you are currently using is not compatible with Full Site Editing.' ) );
+}
+
+/**
+ * Do a server-side redirection if missing `postType` and `postId`
+ * query args when visiting Site Editor.
+ */
+$home_template = _resolve_home_block_template();
+if ( $home_template && empty( $_GET['postType'] ) && empty( $_GET['postId'] ) ) {
+	if ( ! empty( $_GET['styles'] ) ) {
+		$home_template['styles'] = sanitize_key( $_GET['styles'] );
+	}
+	$redirect_url = add_query_arg(
+		$home_template,
+		admin_url( 'site-editor.php' )
+	);
+	wp_safe_redirect( $redirect_url );
+	exit;
+}
+
+// Used in the HTML title tag.
+$title       = __( 'Editor (beta)' );
+$parent_file = 'themes.php';
+
+// Flag that we're loading the block editor.
+$current_screen = get_current_screen();
+$current_screen->is_block_editor( true );
+
+// Default to is-fullscreen-mode to avoid jumps in the UI.
+add_filter(
+	'admin_body_class',
+	static function( $classes ) {
+		return "$classes is-fullscreen-mode";
+	}
+);
+
+$indexed_template_types = array();
+foreach ( get_default_block_template_types() as $slug => $template_type ) {
+	$template_type['slug']    = (string) $slug;
+	$indexed_template_types[] = $template_type;
+}
+
+$block_editor_context = new WP_Block_Editor_Context( array( 'name' => 'core/edit-site' ) );
+$custom_settings      = array(
+	'siteUrl'                  => site_url(),
+	'postsPerPage'             => get_option( 'posts_per_page' ),
+	'styles'                   => get_block_editor_theme_styles(),
+	'defaultTemplateTypes'     => $indexed_template_types,
+	'defaultTemplatePartAreas' => get_allowed_block_template_part_areas(),
+	'__unstableHomeTemplate'   => $home_template,
+);
+
+// Add additional back-compat patterns registered by `current_screen` et al.
+$custom_settings['__experimentalAdditionalBlockPatterns']          = WP_Block_Patterns_Registry::get_instance()->get_all_registered( true );
+$custom_settings['__experimentalAdditionalBlockPatternCategories'] = WP_Block_Pattern_Categories_Registry::get_instance()->get_all_registered( true );
+
+$editor_settings      = get_block_editor_settings( $custom_settings, $block_editor_context );
+
+if ( isset( $_GET['postType'] ) && ! isset( $_GET['postId'] ) ) {
+	$post_type = get_post_type_object( $_GET['postType'] );
+	if ( ! $post_type ) {
+		wp_die( __( 'Invalid post type.' ) );
+	}
+}
+
+$active_global_styles_id = WP_Theme_JSON_Resolver::get_user_global_styles_post_id();
+$active_theme            = wp_get_theme()->get_stylesheet();
+$preload_paths           = array(
+	array( '/wp/v2/media', 'OPTIONS' ),
+	'/wp/v2/types?context=view',
+	'/wp/v2/types/wp_template?context=edit',
+	'/wp/v2/types/wp_template-part?context=edit',
+	'/wp/v2/templates?context=edit&per_page=-1',
+	'/wp/v2/template-parts?context=edit&per_page=-1',
+	'/wp/v2/themes?context=edit&status=active',
+	'/wp/v2/global-styles/' . $active_global_styles_id . '?context=edit',
+	'/wp/v2/global-styles/' . $active_global_styles_id,
+	'/wp/v2/global-styles/themes/' . $active_theme,
+);
+
+block_editor_rest_api_preload( $preload_paths, $block_editor_context );
+
+wp_add_inline_script(
+	'wp-edit-site',
+	sprintf(
+		'wp.domReady( function() {
+			wp.editSite.initializeEditor( "site-editor", %s );
+		} );',
+		wp_json_encode( $editor_settings )
+	)
+);
+
+// Preload server-registered block schemas.
+wp_add_inline_script(
+	'wp-blocks',
+	'wp.blocks.unstable__bootstrapServerSideBlockDefinitions(' . wp_json_encode( get_block_editor_server_block_settings() ) . ');'
+);
+
+wp_add_inline_script(
+	'wp-blocks',
+	sprintf( 'wp.blocks.setCategories( %s );', wp_json_encode( get_block_categories( $post ) ) ),
+	'after'
+);
+
+wp_enqueue_script( 'wp-edit-site' );
+wp_enqueue_script( 'wp-format-library' );
+wp_enqueue_style( 'wp-edit-site' );
+wp_enqueue_style( 'wp-format-library' );
+wp_enqueue_media();
+
+if (
+	current_theme_supports( 'wp-block-styles' ) ||
+	( ! is_array( $editor_styles ) || count( $editor_styles ) === 0 )
+) {
+	wp_enqueue_style( 'wp-block-library-theme' );
+}
+
+/** This action is documented in wp-admin/edit-form-blocks.php */
+do_action( 'enqueue_block_editor_assets' );
+
+require_once ABSPATH . 'wp-admin/admin-header.php';
+?>
+
+<div id="site-editor" class="edit-site"></div>
+
+<?php
+
+require_once ABSPATH . 'wp-admin/admin-footer.php';