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>

src/Plugin.php

@@ -0,0 +1,163 @@
+<?php
+/**
+ * Main Plugin class
+ *
+ * @package Jeremias\WcLicensedProduct
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct;
+
+use Jeremias\WcLicensedProduct\Admin\AdminController;
+use Jeremias\WcLicensedProduct\Api\RestApiController;
+use Jeremias\WcLicensedProduct\Checkout\CheckoutController;
+use Jeremias\WcLicensedProduct\Frontend\AccountController;
+use Jeremias\WcLicensedProduct\License\LicenseManager;
+use Jeremias\WcLicensedProduct\Product\LicensedProductType;
+use Twig\Environment;
+use Twig\Loader\FilesystemLoader;
+
+/**
+ * Main plugin controller
+ */
+final class Plugin
+{
+    /**
+     * Singleton instance
+     */
+    private static ?Plugin $instance = null;
+
+    /**
+     * Twig environment
+     */
+    private Environment $twig;
+
+    /**
+     * License manager
+     */
+    private LicenseManager $licenseManager;
+
+    /**
+     * Get singleton instance
+     */
+    public static function instance(): Plugin
+    {
+        if (self::$instance === null) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    /**
+     * Private constructor for singleton
+     */
+    private function __construct()
+    {
+        $this->initTwig();
+        $this->initComponents();
+        $this->registerHooks();
+    }
+
+    /**
+     * Initialize Twig environment
+     */
+    private function initTwig(): void
+    {
+        $loader = new FilesystemLoader(WC_LICENSED_PRODUCT_PLUGIN_DIR . 'templates');
+        $this->twig = new Environment($loader, [
+            'cache' => WP_CONTENT_DIR . '/cache/wc-licensed-product/twig',
+            'auto_reload' => WP_DEBUG,
+        ]);
+
+        // Add WordPress functions as Twig functions
+        $this->twig->addFunction(new \Twig\TwigFunction('__', function (string $text, string $domain = 'wc-licensed-product'): string {
+            return __($text, $domain);
+        }));
+
+        $this->twig->addFunction(new \Twig\TwigFunction('esc_html', 'esc_html'));
+        $this->twig->addFunction(new \Twig\TwigFunction('esc_attr', 'esc_attr'));
+        $this->twig->addFunction(new \Twig\TwigFunction('esc_url', 'esc_url'));
+        $this->twig->addFunction(new \Twig\TwigFunction('wp_nonce_field', 'wp_nonce_field', ['is_safe' => ['html']]));
+        $this->twig->addFunction(new \Twig\TwigFunction('admin_url', 'admin_url'));
+        $this->twig->addFunction(new \Twig\TwigFunction('wc_get_endpoint_url', 'wc_get_endpoint_url'));
+    }
+
+    /**
+     * Initialize plugin components
+     */
+    private function initComponents(): void
+    {
+        $this->licenseManager = new LicenseManager();
+
+        // Initialize controllers
+        new LicensedProductType();
+        new CheckoutController($this->licenseManager);
+        new AccountController($this->twig, $this->licenseManager);
+        new RestApiController($this->licenseManager);
+
+        if (is_admin()) {
+            new AdminController($this->twig, $this->licenseManager);
+        }
+    }
+
+    /**
+     * Register plugin hooks
+     */
+    private function registerHooks(): void
+    {
+        // Generate license on order completion
+        add_action('woocommerce_order_status_completed', [$this, 'onOrderCompleted']);
+    }
+
+    /**
+     * Handle order completion - generate licenses
+     */
+    public function onOrderCompleted(int $orderId): void
+    {
+        $order = wc_get_order($orderId);
+        if (!$order) {
+            return;
+        }
+
+        foreach ($order->get_items() as $item) {
+            $product = $item->get_product();
+            if ($product && $product->is_type('licensed')) {
+                $domain = $order->get_meta('_licensed_product_domain');
+                if ($domain) {
+                    $this->licenseManager->generateLicense(
+                        $orderId,
+                        $product->get_id(),
+                        $order->get_customer_id(),
+                        $domain
+                    );
+                }
+            }
+        }
+    }
+
+    /**
+     * Get Twig environment
+     */
+    public function getTwig(): Environment
+    {
+        return $this->twig;
+    }
+
+    /**
+     * Get license manager
+     */
+    public function getLicenseManager(): LicenseManager
+    {
+        return $this->licenseManager;
+    }
+
+    /**
+     * Render a Twig template
+     */
+    public function render(string $template, array $context = []): string
+    {
+        return $this->twig->render($template, $context);
+    }
+}