feat(ui): Support @ prefix in URL routing

- Add handling for URLs starting with `@` character
    - Strip `@` prefix to allow direct URL access bypassing urlprefix

ui/vbase.js

@@ -384,8 +384,9 @@ class VBase {
       } else {
         url = String(input);
       }
-
-      if (urlprefix && !url.startsWith('http://') && !url.startsWith('https://')) {
+      if (url.startsWith('@')) {
+        url = url.slice(1)
+      } else if (urlprefix && !url.startsWith('http://') && !url.startsWith('https://')) {
         url = urlprefix + url;
       }