Preserve provider form presentation at runtime

includes/class-static-site-importer-companion-plugin.php

@@ -222,8 +222,13 @@ public static function scaffold( array $payload ) {
 		foreach ( $preserved as $island ) {
 			$files[ $plugin_slug . '/' . $island['relative_src'] ] = $island['content'];
 		}
+		$provider_form_runtime = file_get_contents( __DIR__ . '/class-static-site-importer-provider-form-runtime.php' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- Reads the plugin-owned runtime source carried into generated companions.
+		if ( ! is_string( $provider_form_runtime ) || '' === $provider_form_runtime ) {
+			return new WP_Error( 'static_site_importer_companion_plugin_provider_form_runtime_missing', 'Provider form runtime projection file is unavailable.' );
+		}
+		$files[ $plugin_slug . '/includes/class-static-site-importer-provider-form-runtime.php' ] = $provider_form_runtime;
 
-		$inventory_hash        = substr( hash( 'sha256', (string) wp_json_encode( array( $block_names, $preserved ) ) ), 0, 16 );
+		$inventory_hash        = substr( hash( 'sha256', (string) wp_json_encode( array( $block_names, $preserved, hash( 'sha256', $provider_form_runtime ) ) ) ), 0, 16 );
 		$registration_callback = str_replace( '-', '_', $plugin_slug ) . '_' . $inventory_hash . '_register_blocks';
 		$main_file             = $plugin_slug . '/' . $plugin_slug . '.php';
 		$files                 = array_merge(
@@ -678,6 +683,9 @@ private static function main_plugin_file(
 		$lines[] = sprintf( "define( '%s_DIR', plugin_dir_path( __FILE__ ) );", $const_prefix );
 		$lines[] = sprintf( "define( '%s_URL', plugin_dir_url( __FILE__ ) );", $const_prefix );
 		$lines[] = '';
+		$lines[] = "require_once __DIR__ . '/includes/class-static-site-importer-provider-form-runtime.php';";
+		$lines[] = 'Static_Site_Importer_Provider_Form_Runtime::register();';
+		$lines[] = '';
 		$lines[] = '/**';
 		$lines[] = ' * Register generated blocks from their metadata directories.';
 		$lines[] = ' */';