This extension provides support for Just files in the Zed editor.
I scrapped this together with bits and bobs from other projects for other editors. I don't know how to write Tree Sitter queries and probably can't fix your issues.
I'm happy to accept pull requests to this repository and make releases as needed, but I don't use Just anymore. I've migrated to Mise which doubles as a tool installer and task runner. I've found Mise to be more capable and have much better documentation, both being areas Just was lacking, in my opinion.