Earlier quoted context omitted.
Under GPL3, if you make KendoUI components available via hosted solution, I think you'd have to release your app's entire source. I think GPL3/commercial dual licensing is a very unattractive licensing approach, but that's just my view. CORRECTION: My comment is only true under the Affero GPL.
I think that since the only code that is directly linking to the library is your JS, that needs to be released according to the GPL. So if you don't minify everything, you are probably complying already. Otherwise you'd have to provide access to your unminified JS source.
I'm not certain whether including a GPL library with your JS code requires you to license your JS as well under the GPL, but if it does then simply choosing not to minify won't be enough protection.