Results 4 issues of mlyxshi

Compared to #128, `systemd-initrd` and `traditional initrd` are both supported. `flake` and `systemd-initrd` are non-mandatory. I haven't tested the traditional initrd, I think it should work. >The problem here is...

### Is your feature request related to a problem? Please describe. _No response_ ### Describe the solution you'd like flatpak support https://github.com/xfangfang/wiliwili/discussions/41 ### Describe alternatives you've considered _No response_ ###...

feature

`attic push .#nixosConfigurations.demo.config.system.build.toplevel ` like `nix copy`

It will be convenient to configure attic-client by environment variables (like AWS) in GitHub Actions