✨ Use Github Actions to build packages

[cristianpb]

This PR automates the build process for every device specified in manifest.xml and handles the deployment to GitHub Releases.

While users currently have the option to sideload these packages manually, hosting them on the official Connect IQ Store would provide a much better user experience. Could you please add support for the latest devices and handle the official marketplace submission?

[cristianpb]

An alternative approach would be to adopt a workflow similar to github.com/blackshadev/wayfinder to automate the .iq file build process.

[memen45]

Thank you for this pull request! Automating the building process looks good, although relying on a third party to keep the Garmin sdk files up to date. Some questions I have:

• What is the idea behind the developer key? It seems like the key is generated for each build.
• The action is now triggered by a push. Is that desired or should it be triggered on a version release? How computationally intensive is the build for 60+ devices?
• The update I am finalizing is unfortunately slightly different in structure than the last version in this SubMusic repository. The APIs and sync modules are separated and I have to think about how to combine this pull request with that multi-repo structure.

[cristianpb]

1. I just used a generated key to prove the CI works. You can definitely switch to an encrypted static key using GitHub Secrets later. Check out this workflow blackshadev/wayfinder/.github/workflows/garmin.yml#L11 for a good example of how to handle that.

2. The action is trigger by a push right now for easy testing, but it can be changed to trigger on releases instead. It’s pretty fast, it only takes about 2 minutes to build for all 67 devices. You can see the action logs here: github.com/cristianpb/SubMusic/actions/runs/21743352322

3. I noticed the shift in development toward Submusic for Plex, which uses a different configuration. However, since this repository has been inactive for two years, my primary goal was simply to bring the app up to date for newer devices. If you're looking into a multi-repo approach, this example https://github.com/blackshadev/wayfinder/blob/main/.github/workflows/server.yml shows a great way to manage a proxy server and the CI app simultaneously.