feat: add UserModel::getReturnType() and RegisterController::getUserEntity() uses it

docs/customization/user_provider.md

@@ -54,3 +54,14 @@ class UserModel extends ShieldUserModel
     }
 }
 ```
+
+## Using a Custom User Entity
+
+If you have set a custom `$returnType` in your custom `UserModel`, you may
+retrieve the return type using the `UserModel::getReturnType()` method and
+easily create a new User Entity using it:
+
+```php
+$userEntityClass = $userModel->getReturnType();
+$newUser         = new $userEntityClass();
+```

src/Controllers/RegisterController.php

@@ -163,7 +163,10 @@ protected function getUserProvider(): UserModel
      */
     protected function getUserEntity(): User
     {
-        return new User();
+        $userProvider    = $this->getUserProvider();
+        $userEntityClass = $userProvider->getReturnType();
+
+        return new $userEntityClass();
     }
 
     /**

src/Models/UserModel.php

@@ -395,4 +395,14 @@ private function checkReturnType(): void
             throw new LogicException('Return type must be a subclass of ' . User::class);
         }
     }
+
+    /**
+     * Returns User Entity Type
+     *
+     * @return class-string<User>
+     */
+    public function getReturnType(): string
+    {
+        return $this->returnType;
+    }
 }