Spec: Custom Checkout Fields via Checkout Blocks Extensibility API

<?php
declare(strict_types=1);

use Automattic\WooCommerce\Blocks\Integrations\IntegrationInterface;

class WC_Checkout_Fields_Integration implements IntegrationInterface {
    public function get_name(): string {
        return 'wc-custom-b2b-fields';
    }

    public function initialize(): void {
        $script_asset_path = dirname(__DIR__) . '/build/index.asset.php';
        $script_info = file_exists($script_asset_path) 
            ? require $script_asset_path 
            : ['dependencies' => [], 'version' => '1.0.0'];

        wp_register_script(
            'wc-custom-b2b-fields-frontend',
            plugins_url('build/index.js', dirname(__FILE__)),
            $script_info['dependencies'],
            $script_info['version'],
            true
        );
    }

    public function get_script_handles(): array {
        return ['wc-custom-b2b-fields-frontend'];
    }

    public function get_editor_script_handles(): array {
        return ['wc-custom-b2b-fields-frontend'];
    }

    public function get_script_data(): array {
        return [
            'defaultType' => 'individual',
            'i18n'        => [
                'b2bTitle' => __('Реквизиты организации', 'agenticlab'),
                'innLabel' => __('ИНН компании', 'agenticlab'),
            ]
        ];
    }
}