chore: [app-router-migration-3] apps/[slug]/index, apps/[slug]/setup (#12620)

Co-authored-by: Omar López <zomars@me.com>

.env.example

@@ -294,4 +294,6 @@ E2E_TEST_OIDC_USER_PASSWORD=
 AB_TEST_BUCKET_PROBABILITY=50
 # whether we redirect to the future/event-types from event-types or not
 APP_ROUTER_EVENT_TYPES_ENABLED=1
-APP_ROUTER_SETTINGS_ADMIN_ENABLED=1
+APP_ROUTER_SETTINGS_ADMIN_ENABLED=1
+APP_ROUTER_APPS_SLUG_ENABLED=1
+APP_ROUTER_APPS_SLUG_SETUP_ENABLED=1