App installer GUI installs Ungoogled Chromium from the AUR instead of CachyOS repos

Ran into this while walking a friend through installing CachyOS, they're coming in from Windows with fresh eyes so I figured I'd take notes on all the little weird things they ran into. Compiling an entire web browser from source is pretty unnecessary, and ideally it would also be installing the dependency for the web store to work as well as someone relying on the GUI would expect to be able to use extensions and would not think to go looking for that dependency.

It looks like PDFMod, Whatsapp web, and Slack web aren't available in any repos anymore and can't actually be installed. gtkspell, pidgin-gtkui, hexchat, backintime, simplescreenrecorder, deadbeef, xplayer-plparser, xplayer, sdl2_pango, tuxpaint, pinta, ms-365-electron-bin, opera, and midori are also installing from the AUR, but they're not available in the cachyOS repos so that's to be expected.

Start by reproducing the Ungoogled Chromium installation through the App installer GUI and inspect how it selects between CachyOS repositories and the AUR. Compare the selected package and its dependencies with the available CachyOS repository packages; done means the GUI installs the repository version and includes the dependency needed for web-store extensions.

Written by the indexing model from the issue text.