> The code is available on GitHub. Initially, I wanted to make it fully Open Source, but then I realized anyone could just fork it, slap a paywall on it, and repeat the exact cycle I'm trying to break (maybe highly unlikely, but just in case).

The GitHub is Apache licensed, what is not fully open source about the repo?

Good catch. The GitHub UI flags it as Apache, but if you check the actual LICENSE file, it has the Commons Clause appended to restrict commercial use. That's why I consider it 'Source-Available' rather than strictly Open Source.