Fix Support for m3u8 Playlist Files

[JeffreyGaydos]

It appears the readonly array supportedPlaylistExtensions was intended to have m3u and m3u8 (not flac). From what I can tell this array is used in the validation step for reading playlists in the Dopamine playlist folder. I came to this conclusion when I stumbled upon this line of code:

dopamine/src/app/services/playlist/playlist-decoder.ts

Lines 14 to 19 in 0328c3a

	if (
	this.fileAccess.getFileExtension(playlistPath) === FileFormats.m3u ||
	this.fileAccess.getFileExtension(playlistPath) === FileFormats.m3u8
	) {
	playlistEntries = await this.decodeM3uPlaylistAsync(playlistPath);
	}

Which is attempting to parse playlist files and accepts both the m3u and m3u8 extensions. It appears Dopamine supports UTF-8 encodings fine so I don't see why it would explicitly restrict m3u8 files in the validation step, but please enlighten me if I am wrong.

Without this change, Dopamine does not recognize m3u8 playlist files when placed in the playlist folder. I tested this change using Windows 11, node 20.19.5, npm 11.6.2 and confirmed the playlist appeared and played music from an m3u8 playlist file.

Before Changes	After Changes

See #907

[digimezzo]

@JeffreyGaydos Thanks for this fix! Flac should never have been in there and it was supposed to be m3u8 all along. Just a silly mistake from my part.

[JeffreyGaydos]

You're welcome! Feels great to be an official contributor to this awesome project