// Shortcode pour l'initiation de commande
add_shortcode('miassar_payment_initiate_transaction', 'miassar_payment_initiate_transaction_shortcode');
function miassar_payment_initiate_transaction_shortcode() {
    if (!is_user_logged_in()) {
        return '<p>🔐 Veuillez vous <a href="' . wp_login_url(get_permalink()) . '">connecter</a> pour accéder à cette page.</p>';
    }
    
    $template_path = MIASSAR_PAYMENT_PLUGIN_DIR . 'templates/vendor/initiate-transaction.php';
    if (file_exists($template_path)) {
        ob_start();
        include $template_path;
        return ob_get_clean();
    } else {
        return '<p>❌ Le template est manquant. Veuillez contacter l\'administrateur.</p>';
    }
}
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<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /var/www/html/wordpress/wp-content/plugins/miassar-payment-system/miassar-payment-system.php:228) in <b>/var/www/html/wordpress/wp-includes/pluggable.php</b> on line <b>1535</b><br />
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<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /var/www/html/wordpress/wp-content/plugins/miassar-payment-system/miassar-payment-system.php:228) in <b>/var/www/html/wordpress/wp-includes/pluggable.php</b> on line <b>1538</b><br />