Reject all external routes when parsing a route (#1272)

* reject all external routes when parsing a route

* fix children routers

packages/router-macro/src/route_tree.rs

@@ -367,7 +367,7 @@ impl<'a> RouteTreeSegmentData<'a> {
                         let child_name = &child.ident;
 
                         quote! {
-                            let mut trailing = String::new();
+                            let mut trailing = String::from("/");
                             for seg in segments.clone() {
                                 trailing += seg;
                                 trailing += "/";