fix: make OctaneListener invokable for Laravel event dispatcher

Laravel's event dispatcher expects listener classes to be invokable
(have __invoke method) when registered as a class name string.

The OctaneListener was using a handle() method which caused the
listener to never be invoked, resulting in notification state leaking
between Octane requests.

Renamed handle() to __invoke() to fix the issue.

src/Laravel/EventListener/OctaneListener.php

@@ -9,7 +9,7 @@ use Laravel\Octane\Events\RequestReceived;
 
 final readonly class OctaneListener
 {
-    public function handle(RequestReceived $event): void
+    public function __invoke(RequestReceived $event): void
     {
         /** @var NotificationLoggerListener $listener */
         $listener = $event->sandbox->make('flasher.notification_logger_listener');

tests/Laravel/EventListener/OctaneListenerTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flasher\Tests\Laravel\EventListener;
+
+use Flasher\Laravel\EventListener\OctaneListener;
+use PHPUnit\Framework\TestCase;
+
+final class OctaneListenerTest extends TestCase
+{
+    public function testListenerIsInvokable(): void
+    {
+        $listener = new OctaneListener();
+
+        // Verify the listener is invokable (has __invoke method)
+        // This is crucial for Laravel's event dispatcher to call it correctly
+        $this->assertTrue(is_callable($listener));
+    }
+
+    public function testListenerHasInvokeMethod(): void
+    {
+        // Verify the __invoke method exists and has the correct signature
+        $reflection = new \ReflectionClass(OctaneListener::class);
+
+        $this->assertTrue($reflection->hasMethod('__invoke'));
+
+        $method = $reflection->getMethod('__invoke');
+        $this->assertTrue($method->isPublic());
+
+        $parameters = $method->getParameters();
+        $this->assertCount(1, $parameters);
+        $this->assertSame('event', $parameters[0]->getName());
+    }
+}