[BUG] Images from symlinked directory not visible in Wallpaper panel when using "Flatten" option

Submission checklist

• I have searched existing issues and confirmed this is not a duplicate.
• I am using the latest available version of Noctalia.

Bug description

I've symlinked the directory /usr/share/wallpapers/cachyos-wallpapers into ~/Pictures/Wallpapers/cachyos-wallpapers. I can navigate to both the symlinked directory and my other directory (local) in ~/Pictures/Wallpapers without using the "Flatten" feature.

When i press "Flatten" in the Wallpaper panel, only images from my other directory (which is not a symlink) are shown.

Steps to reproduce

1. Make a symlink to another directory containing image(s) e.g: ln -s </path/to/directory> ~/Pictures/Wallpapers/more-images
2. Open the Wallpaper panel
3. Press the Flatten button

Expected behavior

The symlinked folder to behave the same as the local folder in the same directory.

Actual behavior

I wanted to add the default CachyOS wallpapers alongside my wallpapers in ~/Pictures/Wallpapers. Instead of creating duplicate files (copying from /usr/share/wallpapers/cachyos-wallpapers) i wanted to use symlinks.

Logs / error output

Noctalia version

v5.1.0

Compositor

Niri

Distribution

Arch-based

Environment information

Installed via `cachyos-extra-v3` repository.

Additional context

No response