refactor(frontend): scripts -> utility

packages/frontend/src/utility/media-has-audio.ts

@@ -0,0 +1,14 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export default async function hasAudio(media: HTMLMediaElement) {
+	const cloned = media.cloneNode() as HTMLMediaElement;
+	cloned.muted = (cloned as typeof cloned & Partial<HTMLVideoElement>).playsInline = true;
+	cloned.play();
+	await new Promise((resolve) => cloned.addEventListener('playing', resolve));
+	const result = !!(cloned as any).audioTracks?.length || (cloned as any).mozHasAudio || !!(cloned as any).webkitAudioDecodedByteCount;
+	cloned.remove();
+	return result;
+}