Remote activation

[srid]

• [x] Initial prototype
• [ ] Test it sufficiently in real-world deployments, adjust spec, and merge
  • [x] Works for macOS (nix-darwin)
  • [x] Works for NixOS
  • [x] Secrets (sops agenix)
  • [x] Propagate --override-input
  • [x] Mono-repo of multiple hosts in multiple sub-flakes (e.g.: https://github.com/juspay/nixos-buffet)
  • [x] Mono-repo of multiple hosts in single flake (e.g.: https://github.com/srid/nixos-config)
    • Will require multiple sshTarget options!
  • [ ] Unification
  • [x] Overload .#activate to do remote deployment by taking hostname as argument
  • [ ] Overload .#activate to replace for .#activate-home (#18) and implement per-host configs (#19) ?
  • [x] Refactor Nu & review UX
  • [ ] ... ?
• [x] Docs
  • [x] Clarify non-goals (such as rollbacks)

[srid]

• [ ] Overload .#activate to replace for .#activate-home (Remove .#activate-home in favour of --home argument #18) and implement per-host configs (Per-host home-manager configurations #19) ?

I think I'll merge this PR and do the above in separate PR.

[srid]

https://community.flake.parts/nixos-flake/activate#remote