add element endpoint

backend/app/Controllers/ElementController.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace App\Controllers;
+
+use App\Element\ElementRepository;
+use Illuminate\Http\JsonResponse;
+
+class ElementController
+{
+    public function __construct(private ElementRepository $elementRepository)
+    {
+    }
+
+    public function show(int $id): JsonResponse
+    {
+        $element = $this->elementRepository->find($id);
+
+        return new JsonResponse([
+            'element' => [
+                'id' => $element->getId(),
+                'title' => $element->getTitle(),
+            ],
+        ], 200);
+    }
+}

backend/routes/api.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Controllers\AuthController;
+use App\Controllers\ElementController;
 use App\Controllers\SetController;
 use App\Http\Middleware\AuthMiddleware;
 use Illuminate\Support\Facades\Route;
@@ -10,3 +11,4 @@ Route::post('/logout', [AuthController::class, 'logout']);
 Route::get('/me', [AuthController::class, 'me'])
     ->middleware(AuthMiddleware::class);
 Route::get('/sets', [SetController::class, 'index']);
+Route::get('/elements/{id}', [ElementController::class, 'show']);