chore: major code cleanup and type safety using phpstan

tests/Validator/Constraints/RoomSelectionValidatorTest.php

@@ -12,6 +12,9 @@ use App\Validator\Constraints\RoomSelection;
 use App\Validator\Constraints\RoomSelectionValidator;
 use Symfony\Component\Validator\Test\ConstraintValidatorTestCase;
 
+/**
+ * @extends ConstraintValidatorTestCase<RoomSelectionValidator>
+ */
 class RoomSelectionValidatorTest extends ConstraintValidatorTestCase
 {
     protected function createValidator(): RoomSelectionValidator