Fix router-types

Author: NullVoxPopuli

ui/src/router.ts

@@ -1,6 +1,6 @@
 import type { RouterDSL } from '@ember/-internals/routing';
 
-export function addRoutes(context: RouterDSL): void {
+export function addRoutes(context: Pick<RouterDSL, 'route'>): void {
   /**
    * We need a level of nesting for every `/` in the URL so that we don't over-refresh / render the whole page
    */