add element descriptions

backend/app/Element/UseCases/CreateElement/CreateElement.php

@@ -30,6 +30,7 @@ class CreateElement
         if ($request->title === null || $request->title === '') {
             throw new BadRequestException('title is required');
         }
+        $description = $request->description ?? '';
 
         $set = $this->setRepo->find($request->setId);
         if ($set === null) {
@@ -44,6 +45,7 @@ class CreateElement
             return $this->elementRepo->create(new CreateElementDto(
                 set: $set,
                 title: $request->title,
+                description: $description,
                 parentElement: null,
             ));
         }
@@ -65,6 +67,7 @@ class CreateElement
         return $this->elementRepo->create(new CreateElementDto(
             set: $set,
             title: $request->title,
+            description: $description,
             parentElement: $parentElement,
         ));
     }

backend/app/Element/UseCases/CreateElement/CreateElementRequest.php

@@ -7,6 +7,7 @@ class CreateElementRequest
     public function __construct(
         public ?int $setId,
         public ?string $title,
+        public ?string $description,
         public ?int $parentElementId,
     ) {
     }