this is a nice software, but not notable enough for us to package in Homebrew for now. This is not a decision on the merits of the software, but we cannot distribute every single piece of software and have to draw a line on “notability” somewhere. Of course, we would be happy to reconsider in the future.
In https://github.com/Homebrew/homebrew-core/pull/165860 the PR to add harbor CLI to Homebrew was rejected, we should try this again, once we reach a certain maturity and recognition in the community.