feat(firewall): show current IP address in plugin settings

Adds CurrentIpField that displays the admin's IP with a copy button,
making it easy to add to the Trusted IPs list. Shown at the top of
the firewall plugin's Network & Session fieldset.

source/packages/plg_system_mokosuiteclient_firewall/mokosuiteclient_firewall.xml

@@ -33,12 +33,17 @@
 	</languages>
 
 	<config>
-		<fields name="params">
+		<fields name="params"
+			addfieldprefix="Moko\Plugin\System\MokoSuiteClientFirewall\Field">
 			<!-- Network & Session -->
 			<fieldset name="basic"
 				label="PLG_SYSTEM_MOKOSUITECLIENT_FIREWALL_FIELDSET_BASIC"
 				description="PLG_SYSTEM_MOKOSUITECLIENT_FIREWALL_FIELDSET_BASIC_DESC">
 
+				<field name="current_ip_display" type="CurrentIp"
+					label="Your Current IP Address"
+					description="This is the IP address you are connecting from. Copy it to add to the Trusted IPs list below." />
+
 				<field name="force_https" type="radio" default="1"
 					label="PLG_SYSTEM_MOKOSUITECLIENT_FIREWALL_FORCE_HTTPS_LABEL"
 					description="PLG_SYSTEM_MOKOSUITECLIENT_FIREWALL_FORCE_HTTPS_DESC"

source/packages/plg_system_mokosuiteclient_firewall/src/Field/CurrentIpField.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * @package     MokoSuiteClient
+ * @subpackage  plg_system_mokosuiteclient_firewall
+ */
+
+namespace Moko\Plugin\System\MokoSuiteClientFirewall\Field;
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Form\FormField;
+
+/**
+ * Read-only field that displays the current user's IP address.
+ * Useful for quickly copying the IP to add to trusted IPs list.
+ */
+class CurrentIpField extends FormField
+{
+	protected $type = 'CurrentIp';
+
+	protected function getInput(): string
+	{
+		$ip = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? '';
+
+		if (!empty($ip))
+		{
+			$ip = trim(explode(',', $ip)[0]);
+		}
+
+		if (empty($ip))
+		{
+			$ip = $_SERVER['REMOTE_ADDR'] ?? '0.0.0.0';
+		}
+
+		return '<div class="d-flex align-items-center gap-2">'
+			. '<code style="font-size:1.1rem;padding:0.4rem 0.8rem;background:#f8f9fa;border:1px solid #dee2e6;border-radius:4px;" id="mokosuiteclient-current-ip">'
+			. htmlspecialchars($ip)
+			. '</code>'
+			. '<button type="button" class="btn btn-sm btn-outline-secondary" onclick="navigator.clipboard.writeText(document.getElementById(\'mokosuiteclient-current-ip\').textContent.trim()).then(function(){this.textContent=\'Copied!\';var b=this;setTimeout(function(){b.textContent=\'Copy\'},1500)}.bind(this))" title="Copy IP to clipboard">Copy</button>'
+			. '</div>';
+	}
+}