feat(bookstack) : add BookStackShelf API resource for listing shelves

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ApiResource/BookStackShelf.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ApiResource;
+
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\Metadata\GetCollection;
+use App\State\BookStackShelfProvider;
+use Symfony\Component\Serializer\Attribute\Groups;
+
+#[ApiResource(
+    operations: [
+        new GetCollection(
+            uriTemplate: '/bookstack/shelves',
+            normalizationContext: ['groups' => ['bookstack_shelf:read']],
+            provider: BookStackShelfProvider::class,
+            security: "is_granted('ROLE_ADMIN')",
+        ),
+    ],
+)]
+final class BookStackShelf
+{
+    #[Groups(['bookstack_shelf:read'])]
+    public int $id = 0;
+
+    #[Groups(['bookstack_shelf:read'])]
+    public string $name = '';
+}