Added missing copyright note

Signed-off-by: Mike Lischke <mike@lischke-online.de>

Author: mike-lischke

tests/e2e/playback-display.spec.ts

@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Mike Lischke. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ */
+
 import { expect, test } from "@playwright/test";
 
 import { expectPlaybackToMove, routeApi } from "./helpers.js";