Hy, thank you for your reply.
I was thinking about raspberry, but I`m concerned about boot time, stability and porting my display code to it, I also have zero experience with raspberry... this should be possible without linux.
I might try to use DFPlayer mini along with some other usb reader and make it work in a way that arduino would first read the txt file of filenames and copy it into array on power on, then switch to DFplayer and display filenames from that array.
And finaly I would make simple windows software that would copy my songs to flash drive, auto-rename them for DFplayer file-name-standard and auto-generate the playlist.txt file.
I didnt do any research, but just from top of my head: This could be the exact reason why older Apple products needed iTunes to sync music onto their devices? File indexing?