@Bajax git checkout . doesn't reset anything I don't think, git reset --hard is the proper way but I'm not an expert. It's 3am here, maybe something went wrong with npm again but I suspect your manual manipulations altered the package json and lockfile causing issues, I'll checkafder I wake up.

If you just want recent develop build it should be here https://git.pleroma.social/pleroma/pleroma-fe/-/jobs/240362/artifacts/browse