Respect CODEX_HOME when installing the Codex skill

[fAntel]

I keep my Codex home directory on an external SSD because my MacBook has limited internal storage. Codex officially supports this through CODEX_HOME environment variable (https://learn.chatgpt.com/docs/config-file/environment-variables#core-locations).

However, agterm’s Help-menu skill installer currently checks for ~/.codex and installs under that path, so it doesn’t detect or target my custom Codex home.

Would you accept a change that uses CODEX_HOME for both detection and installation when set, with ~/.codex as the fallback?

The Codex plugin works around this for me, but supporting the documented location override would make the built-in installer work with this setup too. I’d be happy to submit a focused PR with tests if this approach is approved.

[umputun]

yes, for the case where CODEX_HOME is set. With it unset nothing should change, the default ~/.codex install stays as is.

I turned the same ask down in #315, mostly because a Dock-launched app never sees variables from the shell rc. That part is solvable now: the OpenCode hooks installer already reads its config dir through a login shell (agterm/OpenCodeEnvironmentProbe.swift), and the same probe can return CODEX_HOME too.

what I'd take in one PR:

• read CODEX_HOME from that login-shell probe, one run for both the skill and the hooks installer. An empty value counts as unset, as in Codex, and a failed or timed-out probe falls back to ~/.codex
• Codex detection, the skill install ($CODEX_HOME/skills/agterm) and the Codex hooks merge (AgentHooksInstaller.mergeCodexConfig) all use that resolved directory
• with CODEX_HOME unset, every path and message stays exactly as it is now
• the result dialogs name the directory actually used
• the public helpers in agtermCore/Sources/agtermCore/SkillInstall.swift keep their signatures, add an overload instead. The agterm-linux fork builds against them

if that works for you, pls go ahead with the PR.

[fAntel]

Thanks. I'm on it. Should I close the discussion now or when PR will be accepted/declined?

[umputun]

keep it open, pls. Put the discussion URL in the PR description, and I'll close it here once the PR is merged or closed.

[umputun]

merged in #905, it will be in the next release. Export CODEX_HOME in your shell rc, then run Help ▸ Install Agent Skill… and Help ▸ Install Agent Status Hooks…. Both read it through your login shell, and the result dialog names the directory they used. An unset or empty value keeps ~/.codex, and a missing custom directory is skipped with a note instead of falling back to ~/.codex.

agterm-server install-hooks on a Linux host doesn't read CODEX_HOME yet, that one is on my list.