fix(switching): improve account switching reliability and UX

[Fzhiyu1]

Summary

• improve account switching UX with an in-app confirmation modal and a Switch New Sessions Only option
• ignore Codex.app app-server when detecting blocking Codex foreground processes and surface switching failures in the UI
• reclaim stale ~/.codex/auth.json.lock files left behind by dead processes

Test Plan

• node --test --experimental-strip-types tests/switching.test.ts
• pnpm build
• cargo test auth::fs_utils::tests::acquire_reclaims_stale_lock_file
• cargo test commands::account::tests
• cargo test commands::process::tests

[joonshakya]

In my testing, I was not able to get the account switched properly without needing to quit codex.
I've made a video with the result I found. Can you please let me know if I am missing something?
The video has audio as well.

2026-03-12_09-57-06_compressed_50fps.mp4

[Fzhiyu1]

I watched the video and your observations are basically correct.

What this PR is trying to do is not hot-switch the currently running Codex app / CLI process. The non-restart path is only meant to update the auth for the next launch / next new process, without forcing the current one to restart immediately.

So for Codex.app, needing to fully quit and reopen before the change takes effect is expected with the current implementation.

And for CLI, I also agree with your point about Restart and Switch being disruptive. That was actually the reason I added the non-restart option, because killing an active TUI / terminal session is pretty rough.

I think the confusing part here is the wording. Switch New Sessions Only probably sounds like a new chat inside the already running app should pick up the new account, but that is not what this implementation does.

If that behavior is too confusing or not a good fit for the project, I'm okay reducing the scope of the PR and removing that part.

[joonshakya]

Hi @Fzhiyu1
The previous commit in PR #15 had caused some issues so we're trying to revert that commit in PR #23 .

That version of codex-switcher used to gray out account switching option when Codex.app or Codex CLI was running in the background which is I think the more stable flow.
We do like the idea of switching the model in next session of Codex CLI.

Could you take a look at the code in the main branch and make refinements there, If your changes still align with how the app works right now?
Sorry for the inconvenience.

Thank you for your contribution.