Some improvements

tests/Feature/GameSnapshotTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature;
+
+use App\Events\GameSnapshot;
+use App\Game\Room;
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+final class GameSnapshotTest extends TestCase
+{
+    #[Test]
+    public function broadcast_payload_discloses_message_size_cap(): void
+    {
+        $room = new Room('test');
+
+        $payload = (new GameSnapshot($room, [], [], []))->broadcastWith();
+
+        $this->assertArrayHasKey('msgCap', $payload);
+        $this->assertSame(
+            (int) config('reverb.apps.apps.0.max_message_size', 0),
+            $payload['msgCap'],
+            'client debug HUD reports the same cap the Reverb server enforces',
+        );
+    }
+}