Allow heading tags (h1-h6) in ContentSanitizer so news editor headings render

tests/Feature/Studio/StudioArtworkDescriptionValidationTest.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Artwork;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+
+uses(RefreshDatabase::class);
+
+it('rejects raw html when updating artwork descriptions from studio', function (): void {
+    $user = User::factory()->create();
+    $artwork = Artwork::factory()->for($user)->create([
+        'title' => 'Studio Artwork',
+        'slug' => 'studio-artwork',
+        'description' => 'Original description',
+    ]);
+
+    $this->actingAs($user)
+        ->putJson(route('api.studio.artworks.update', ['id' => $artwork->id]), [
+            'description' => '<img src="https://spam.example/test.jpg" alt="">',
+        ])
+        ->assertStatus(422)
+        ->assertJsonValidationErrors(['description']);
+});