To edit a git commit somewhere before the last one, use rebase with the commit hash (via StackOverflow answer):
Continue reading post "Change git commit"versioning posts
I don’t know why I didn’t realize this before, but git project versions can be managed just with tags rather than needing to create a branch for each point version. Packagist can go entirely by tags. I had been creating point version branches because Symfony does, but that’s really only needed if you need to continue updating a previous version. It’s overkill for small, one person projects. With a tag available, it wouldn’t be hard to create a branch later anyway if needed.