Btw, from the same mpv issue page from which I stole code (https://github.com/mpv-player/mpv/issues/11183), there's a profile-cond version for mpv.conf. It doesn't work exactly how things work in files below, but instead, it instantly will seek to start after reaching eof:

[replay]
profile-cond=eof_reached and pause
input-commands=seek 0 absolute

If you don't mind behavior difference, then it is a nice alternative to .lua version.