add set persistence

backend/app/Set/EloquentSetRepository.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Set;
+
+use App\User\UserRepository;
+use RuntimeException;
+
+class EloquentSetRepository implements SetRepository
+{
+    public function __construct(
+        private UserRepository $userRepository,
+    ) {}
+
+    public function create(CreateSetDto $dto): Set
+    {
+        $model = SetModel::create([
+            'name' => $dto->name,
+            'creator_id' => $dto->creator->getId(),
+        ]);
+
+        return new Set(
+            id: $model->id,
+            name: $model->name,
+            creator: $dto->creator,
+        );
+    }
+
+    public function all(): array
+    {
+        $models = SetModel::query()
+            ->orderBy('name')
+            ->orderBy('id')
+            ->get();
+        $sets = [];
+
+        foreach ($models as $model) {
+            $sets[] = $this->toDomain($model);
+        }
+
+        return $sets;
+    }
+
+    private function toDomain(SetModel $model): Set
+    {
+        $creator = $this->userRepository->find($model->creator_id);
+        if ($creator === null) {
+            throw new RuntimeException('set creator not found');
+        }
+
+        return new Set(
+            id: $model->id,
+            name: $model->name,
+            creator: $creator,
+        );
+    }
+}