Flatpak support

[wiiznokes]

I think this is possible.
Probably need some udev rules like openRGB
https://openrgb.org/udev

flatpak repo: https://github.com/flathub/org.openrgb.OpenRGB

the pull request to flathub of openRGB: flathub/flathub#2677

tauri discussion about flatpak (the file could be generated by cargo packager eventually)

• [feat] Bundle Tauri apps as Flatpak tauri-apps/tauri#3619
• Approach to creating Flatpak bundles tauri-apps/tauri#4426

Process to add flatpak support (doc: https://docs.flatpak.org/en/latest/introduction.html)

• having a manifest file
• find out the runtime we need (i think all app need a runtime (maybe the xdgdesktop one)).
• compile using flatpak-builder (more a packaging apparently), we will need the corresponding sdk of the runtime to do this step)
• pull request to flathub

[wiiznokes]

maybe we will need the nvidia runtime to use wgpu ❓

[wiiznokes]

https://github.com/squidowl/halloy/blob/main/assets/flatpak/org.squidowl.halloy.json

[wiiznokes]

doc for metadata file: https://www.freedesktop.org/software/appstream/docs/
.desktop: https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html

[wiiznokes]

Need to generate a source file for the manifest using https://github.com/flatpak/flatpak-builder-tools.
Using a git repo as a source, and making shell command to init submodule, fetch deps would be better, but a dir source can maybe work.

carreful with the local cache.

[wiiznokes]

https://github.com/flathub/org.squidowl.halloy/blob/master/org.squidowl.halloy.json

[wiiznokes]

https://github.com/flatpak/flatpak-github-actions

[wiiznokes]

https://docs.flathub.org/docs/for-app-authors/metainfo-guidelines/

[wiiznokes]

https://docs.flatpak.org/en/latest/flatpak-builder-command-reference.html#