[rubymamis]

You can check my FOSS note-taking app: https://www.notes-foss.com. It is a native Qt C++ app.

It has a feature that converts your Markdown tasks into a Kanban: https://www.notes-foss.com/videos/kanban.mp4

It doesn't have a built-in sync, but people have told me they managed to sync the DB using Dropbox and other such services.

It has a one time payment option to unlock the Kanban feature, but you can also compile it yourself and get all the Pro features for free (all instructions are on GitHub[1]).

[1] https://github.com/nuttyartist/notes