fix: guard component service calls with class_exists check

System plugin event handlers fire during install before com_mokosuite
is fully loaded. Guard AutomationEngine and NotificationService calls
with class_exists() to prevent fatal errors during package install.

source/packages/plg_system_mokosuite/Extension/MokoSuite.php

@@ -2167,7 +2167,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 	{
 		if (!$isnew || !$success) return;
 
-		\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('user_register', [
+		class_exists(\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::class, true) && \Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('user_register', [
 			'user_id'  => (int) ($user['id'] ?? 0),
 			'username' => $user['username'] ?? '',
 			'email'    => $user['email'] ?? '',
@@ -2182,7 +2182,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 	{
 		if ($context !== 'com_content.article') return;
 
-		\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('content_save', [
+		class_exists(\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::class, true) && \Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('content_save', [
 			'article_id' => (int) ($article->id ?? 0),
 			'title'      => $article->title ?? '',
 			'is_new'     => $isNew ? '1' : '0',
@@ -2196,7 +2196,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 	 */
 	public function onExtensionAfterInstall($installer, $eid): void
 	{
-		\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('extension_install', [
+		class_exists(\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::class, true) && \Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('extension_install', [
 			'extension_id' => (int) $eid,
 		]);
 	}
@@ -2216,7 +2216,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 		$name = $user->username ?? $user->name ?? 'unknown';
 
 		// Fire automation for any login
-		\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('user_login', [
+		class_exists(\Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::class, true) && \Moko\Component\MokoSuite\Administrator\Service\AutomationEngine::fire('user_login', [
 			'user_id'  => (int) ($user->id ?? 0),
 			'username' => $name,
 			'ip'       => $ip,
@@ -2226,7 +2226,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 		// Security notification for backend logins only
 		if (!$this->app->isClient('administrator')) return;
 
-		\Moko\Component\MokoSuite\Administrator\Service\NotificationService::securityAlert(
+		class_exists(\Moko\Component\MokoSuite\Administrator\Service\NotificationService::class, true) && \Moko\Component\MokoSuite\Administrator\Service\NotificationService::securityAlert(
 			'admin_login',
 			"Admin login: {$name}",
 			"User: {$name}\nIP: {$ip}\nTime: " . gmdate('Y-m-d H:i:s') . " UTC"
@@ -2251,7 +2251,7 @@ class MokoSuite extends CMSPlugin implements BootableExtensionInterface
 
 		if ($count >= 3 && $count % 3 === 0)
 		{
-			\Moko\Component\MokoSuite\Administrator\Service\NotificationService::securityAlert(
+			class_exists(\Moko\Component\MokoSuite\Administrator\Service\NotificationService::class, true) && \Moko\Component\MokoSuite\Administrator\Service\NotificationService::securityAlert(
 				'login_failure',
 				"Failed login attempts: {$count} from {$ip}",
 				"Username: {$username}\nIP: {$ip}\nAttempts: {$count}\nTime: " . gmdate('Y-m-d H:i:s') . " UTC"