Pathless Layout Route Renders Empty HTML #3843

Which project does this relate to?

Router

Describe the bug

When defining a pathless layout route (_appLayout.tsx) inside a folder (app/), TanStack Router incorrectly treats it as a route. Instead of returning a Not found when accessing /app, it renders an empty HTML page.

Your Example Website or App

https://stackblitz.com/edit/github-aeat3k26

Steps to Reproduce the Bug or Issue

1. go to the /app route

Expected behavior

Expected: /app should return Not found page (since _appLayout.tsx is pathless).

Actual: /app renders an empty HTML page instead.

Screenshots or Videos

No response

Platform

• OS: [e.g. macOS, Windows, Linux]
• Browser: [e.g. Chrome, Safari, Firefox]
• Version: [e.g. 91.1]

Additional context

No response