Directly publish to Flathub from this repository

I'm aware that there's a repo in the Flathub organization already. However, it's possible to directly publish to Flathub without needing to do the duplicated work like you are doing at the moment.

Mozilla for example builds Firefox in their own infra and only uses Flathub for the publishing part. OBS Studio recently started publishing directly to Flathub without needing to create another repo in the Flathub org, see: https://github.com/obsproject/obs-studio/pull/5569.

I suggest building here on GitLab and only use Flathub to publish the app, instead of doing the duplicated work to commit on both this repo and on the repo in the Flathub org.

I've never done this so unfortunately I don't really know any tips or tricks. Maybe contacting the Flathub devs will help.