fix issue and add test

tests/ManualModeTest.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Support\Facades\Event;
+use Stancl\Tenancy\Events\TenancyInitialized;
+use Stancl\Tenancy\Listeners\CreateTenantConnection;
+use \Stancl\Tenancy\Tests\Etc\Tenant;
+
+test('manual tenancy initialization works', function () {
+    Event::listen(TenancyInitialized::class, CreateTenantConnection::class);
+
+    $tenant = Tenant::create();
+
+    tenancy()->initialize($tenant);
+
+    expect(tenancy()->initialized)->toBeTrue();
+});