Implement version 0.0.1 - Licensed Product type for WooCommerce

Add complete plugin infrastructure for selling software with license keys:

- New "Licensed Product" WooCommerce product type
- License key generation (XXXX-XXXX-XXXX-XXXX format) on order completion
- Domain-based license validation system
- REST API endpoints (validate, status, activate, deactivate)
- Customer My Account "Licenses" page
- Admin license management under WooCommerce > Licenses
- Checkout domain field for licensed products
- Custom database tables for licenses and product versions
- Twig template engine integration
- Full i18n support with German (de_CH) translation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wc-licensed-product.php

@@ -0,0 +1,113 @@
+<?php
+/**
+ * Plugin Name: WC Licensed Product
+ * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-licensed-product
+ * Description: WooCommerce plugin to sell software products using license keys with domain-based validation.
+ * Version: 0.0.1
+ * Author: Marco Graetsch
+ * Author URI: https://src.bundespruefstelle.ch/magdev
+ * License: GPL-2.0-or-later
+ * License URI: https://www.gnu.org/licenses/gpl-2.0.html
+ * Text Domain: wc-licensed-product
+ * Domain Path: /languages
+ * Requires at least: 6.0
+ * Requires PHP: 8.3
+ * WC requires at least: 10.0
+ * WC tested up to: 10.0
+ *
+ * @package Jeremias\WcLicensedProduct
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct;
+
+// Prevent direct access
+if (!defined('ABSPATH')) {
+    exit;
+}
+
+// Plugin constants
+define('WC_LICENSED_PRODUCT_VERSION', '0.0.1');
+define('WC_LICENSED_PRODUCT_PLUGIN_FILE', __FILE__);
+define('WC_LICENSED_PRODUCT_PLUGIN_DIR', plugin_dir_path(__FILE__));
+define('WC_LICENSED_PRODUCT_PLUGIN_URL', plugin_dir_url(__FILE__));
+define('WC_LICENSED_PRODUCT_PLUGIN_BASENAME', plugin_basename(__FILE__));
+
+// Load Composer autoloader
+if (file_exists(WC_LICENSED_PRODUCT_PLUGIN_DIR . 'vendor/autoload.php')) {
+    require_once WC_LICENSED_PRODUCT_PLUGIN_DIR . 'vendor/autoload.php';
+}
+
+/**
+ * Check if WooCommerce is active
+ */
+function wc_licensed_product_is_woocommerce_active(): bool
+{
+    return class_exists('WooCommerce');
+}
+
+/**
+ * Admin notice for missing WooCommerce
+ */
+function wc_licensed_product_woocommerce_missing_notice(): void
+{
+    ?>
+    <div class="error">
+        <p>
+            <?php
+            printf(
+                /* translators: %s: WooCommerce plugin name */
+                esc_html__('%s requires WooCommerce to be installed and active.', 'wc-licensed-product'),
+                '<strong>WC Licensed Product</strong>'
+            );
+            ?>
+        </p>
+    </div>
+    <?php
+}
+
+/**
+ * Initialize the plugin
+ */
+function wc_licensed_product_init(): void
+{
+    // Check for WooCommerce
+    if (!wc_licensed_product_is_woocommerce_active()) {
+        add_action('admin_notices', __NAMESPACE__ . '\\wc_licensed_product_woocommerce_missing_notice');
+        return;
+    }
+
+    // Load text domain
+    load_plugin_textdomain(
+        'wc-licensed-product',
+        false,
+        dirname(WC_LICENSED_PRODUCT_PLUGIN_BASENAME) . '/languages'
+    );
+
+    // Initialize the plugin
+    Plugin::instance();
+}
+
+// Hook into plugins_loaded to ensure WooCommerce is loaded first
+add_action('plugins_loaded', __NAMESPACE__ . '\\wc_licensed_product_init');
+
+// Register activation hook
+register_activation_hook(__FILE__, function (): void {
+    if (!wc_licensed_product_is_woocommerce_active()) {
+        deactivate_plugins(WC_LICENSED_PRODUCT_PLUGIN_BASENAME);
+        wp_die(
+            esc_html__('WC Licensed Product requires WooCommerce to be installed and active.', 'wc-licensed-product'),
+            'Plugin Activation Error',
+            ['back_link' => true]
+        );
+    }
+
+    // Run installation
+    Installer::activate();
+});
+
+// Register deactivation hook
+register_deactivation_hook(__FILE__, function (): void {
+    Installer::deactivate();
+});