Store app password in stamp encrypted data

[jonatanklosko]

Currently we don't persist, but we can use the stamp.

[hugobarauna]

@jonatanklosko if we do that, I'd be able to configure the password for a Livebook app, and once I deploy that app, that password would be persisted there?

[jonatanklosko]

@hugobarauna for Teams, correct! And for personal hub, the machine you deploy to would need to have the same personal secret key.

[hugobarauna]

@jonatanklosko that would be useful! It's better than the current alternative which is to have the same password for all deployed apps using the LIVEBOOK_APPS_PATH_PASSWORD env var.

[jonatanklosko]

Yeah, the idea is that LIVEBOOK_APPS_PATH_PASSWORD could still be used when deploying with personal hub to HuggingFace, similarly to how we pass secrets using env vars (HF secrets). That's because with personal hub, stamping is inherently designed to work within the local user machine. However, with Teams agent deployment the current behaviour would be very confusing (and there's a clear way we can make it work).