Flatpak version cannot create desktop shortcuts due to missing --filesystem:xdg-data/applications entry

Hello!

I'm encountering an issue with the Flatpak version of Minigalaxy where it's unable to create desktop shortcuts during game installation. Specifically, I'm getting a FileNotFoundError in the logs when it tries to create the .desktop file in /home/vertikal/.local/share/applications/.

The full error message is:

**FileNotFoundError: [Errno 2] Nie ma takiego pliku ani katalogu: '/home/vertikal/.local/share/applications/Iron Harvest.desktop'**

I've confirmed that the directory /home/vertikal/.local/share/applications/ exists and has the permissions drwxr-x---. I've also verified that there's no existing Iron Harvest.desktop file in that directory.

A user named GB609 on the [Minigalaxy](https://github.com/sharkwouter/minigalaxy/issues/647#issuecomment-2663515557) forum pointed out that the **Flatpak manifest appears to be missing the --filesystem:xdg-data/applications entry in the finish-args section.** According to Flatpak documentation, this entry is necessary to allow the application to write to the XDG data applications directory. The only file system access the package has is ~/GOG Games which also is pretty limited, considering that this folder can be changed from within minigalaxy.

It seems likely that the missing --filesystem:xdg-data/applications entry is preventing the Flatpak version of Minigalaxy from creating the desktop shortcuts.

**Could you please add the --filesystem:xdg-data/applications entry to the Flatpak manifest?**

Thank you for your time and attention to this issue!