`fullscreen_material` example doesn't render properly with `Hdr` on

## Bevy version and features

main

## What you did

Run `fullscreen_material` example with `Hdr` on.

## What went wrong

<img width="1275" height="749" alt="Image" src="https://github.com/user-attachments/assets/f45b5c98-b072-446a-b90c-f4ef23f41e16" />