Adjust SSH config with action-upterm

[kachick]

Resolves GH-941

[kachick]

Run owenthereal/action-upterm@5501233b996152ba43e22e8c73c39640f9ae2b3c
  with:
    limit-access-to-users: kachick
    limit-access-to-actor: false
    upterm-server: ssh://uptermd.upterm.dev:[2](https://github.com/kachick/dotfiles/actions/runs/12644804898/job/35232959003?pr=1030#step:13:2)2
  env:
    DETERMINATE_NIX_KVM: 1
  
upterm
Error: EACCES: permission denied, open '/home/runner/.ssh/config'

https://github.com/owenthereal/action-upterm/blob/4f618b2f5a28013279fff3413093e31d83c9b074/src/index.ts#L43

> echo '# :)' >>  ~/.ssh/config
zsh: permission denied: /home/kachick/.ssh/config

> la ~/.ssh/config
0777 - 01-06 14:10 /home/kachick/.ssh/config -> /nix/store/c4mh0wnzzsrgy6gbgldim2r7b4am6b28-home-manager-files/.ssh/config

Ah... it is writing entry in home-manager linked config

[kachick]

Next facing to owenthereal/upterm#283

dotfiles/home-manager/ssh.nix

Line 59 in 874d156

controlMaster = "auto";

might be related

[kachick]

https://github.com/nix-community/home-manager/blob/20665c6efa83d71020c8730f26706258ba5c6b2a/modules/programs/ssh.nix#L424-L430

%r in the default makes it longer?

[kachick]

It looks useful such as tmate. I may use it in next fighting with GitHub Actions. It may help issues like GH-905

If then, 3dea898 is the adding code for that workflow.

[kachick]

However no CLI is needed in this dotfiles global for now. I have plan to use it only for GitHub Action debugging.