Maybe a naive question: Why not just run a local server (localhost should be secure)? I mean: You create a web app and kind of a backend / some logic anyway.

Maybe a naive question: Why not just run a local server (localhost should be secure)? I mean: You create a web app and kind of a backend / some logic anyway. You could embed all assets and the server into one executable file and distribute it. The user then runs this executable and uses their default system browser.