Login/logout flow can end on generic “Oops, an error has occurred” page

Description

Codex can fail during the sign-in/sign-out flow and end up on a generic error page instead of completing authentication.

The UI shows:

Oops, an error has occurred
Try again

This appears after using the Codex login/logout flow. Once it happens, the user cannot continue normally from that screen.

Steps to reproduce

1. Sign in to Codex.
2. Sign out.
3. Attempt to sign in again / switch account through the normal authentication flow.
4. Codex displays the generic error page shown above.

Expected behavior

Signing out should fully clear the previous authentication state, and the next sign-in should start a clean authentication flow and complete normally.

Actual behavior

The authentication flow can fail and leave Codex on a generic error screen with only a Try again button.

Environment

• Platform: Windows desktop
• Product: Codex
• Area: authentication / login / logout

Additional context

This looks like stale or inconsistent authentication/session state after logout. A screenshot of the error screen is available and shows only the generic message above, without a more specific error code.

It would also help if the error page exposed a diagnostic/error ID so users can include it in bug reports.

No files, tests, or entry points are named. First reproduce the sign-in, sign-out, and account-switching flow on Windows, then trace the authentication and session-state handling around logout. Done means logout clears the prior state, a subsequent sign-in completes normally, and the generic failure exposes a diagnostic ID if the error remains.