[FEAT] Add a CI/CD Pipeline for a zip build output.

[AWildLeon]

Is your feature request related to a problem? Please describe.
I’ve written an unofficial installer that consumes BetterBahn builds outside of Docker. While this works reliably, there is currently no generic build artifact available, which forces me to extract /app from the Docker image as a workaround.

This makes downstream packaging more complex than necessary and relies on unorthodox extraction steps in installation scripts.

Describe the solution you’d like
Provide a generic build.zip artifact that contains the same contents as /app in the Docker image, produced automatically by CI on each commit (or release).

This would mirror the Docker build output, just in an archive format.

Describe alternatives you’ve considered
Currently, I’m extracting /app directly from the Docker image. While functional, this approach is brittle, indirect, and tightly couples downstream tooling to OCI Tooling even when Docker itself is not used.

Additional context
A generic build artifact would enable:

• community-maintained installers
• distro packaging (e.g. Debian)
• manual installations
• other non-Docker deployment workflows

This does not imply new supported deployment targets; it simply exposes an already-built artifact in a neutral format.

[AWildLeon]

I might come up with a PR if this is a wanted feature.