Use a standardized transformer base; replace all client transformers to call that base

app/Transformers/Api/Client/UserTransformer.php

@@ -4,24 +4,16 @@ namespace Pterodactyl\Transformers\Api\Client;
 
 use Illuminate\Support\Str;
 use Pterodactyl\Models\User;
+use Pterodactyl\Transformers\Api\Transformer;
 
-class UserTransformer extends BaseClientTransformer
+class UserTransformer extends Transformer
 {
-    /**
-     * Return the resource name for the JSONAPI output.
-     */
     public function getResourceName(): string
     {
         return User::RESOURCE_NAME;
     }
 
-    /**
-     * Transforms a User model into a representation that can be shown to regular
-     * users of the API.
-     *
-     * @return array
-     */
-    public function transform(User $model)
+    public function transform(User $model): array
     {
         return [
             'uuid' => $model->uuid,
@@ -29,7 +21,7 @@ class UserTransformer extends BaseClientTransformer
             'email' => $model->email,
             'image' => 'https://gravatar.com/avatar/' . md5(Str::lower($model->email)),
             '2fa_enabled' => $model->use_totp,
-            'created_at' => $model->created_at->toIso8601String(),
+            'created_at' => self::formatTimestamp($model->created_at),
         ];
     }
 }