Hiya!

You can't point to a controller. I would point it to the html file. Then add a js file which would then make a call to the controller. Something like this:

angular.module("umbraco").controller("myCustomDashboard.controller", function ($http) {
       $http.get("/Controllers/Admin/Index").then(function(data){
          //Do stuff
       });
});

package.manifest:

{
  "dashboards":[ ],
  "javascript": [
         "path/to/js/file.js"
   ]
}

Hope that gets you on the right track!

//Johannes