test(factories): add missing model factories for app test suite

Enable `HasFactory` on `Environment`, `Project`, `ScheduledTask`, and
`StandaloneDocker`, and add dedicated factories for related models to
stabilize feature/unit tests.

Also bump `visus/cuid2` to `^6.0` and refresh `composer.lock` with the
resulting dependency updates.

tests/Unit/HealthCheckCommandInjectionTest.php

@@ -5,7 +5,6 @@ use App\Models\Application;
 use App\Models\ApplicationDeploymentQueue;
 use App\Models\ApplicationSetting;
 use Illuminate\Support\Facades\Validator;
-use Mockery;
 
 beforeEach(function () {
     Mockery::close();