[macOS] Detached app-server repeatedly fails OAuth Keychain access with CSSMERR_CSP_NO_USER_INTERACTION

Codex version

0.147.0

Platform

macOS 26.6.1, Apple Silicon

Problem

Two Codex app-server processes remained alive after becoming detached from
their original interactive terminal context. Both had no TTY and were
reparented to PID 1.

During a later OAuth login attempt, the CLI reported:

failed to write OAuth tokens to keyring: Platform secure storage failure:
User interaction is not allowed.

macOS unified logs showed repeated:

CSSMERR_CSP_NO_USER_INTERACTION

The app-servers retried Keychain access approximately once per second. The
login Keychain itself was available and unlocked in the logged-in GUI session.

Neither detached server had an active client connection when inspected.
Gracefully terminating only those stale servers immediately stopped the
Keychain error loop and preserved the tmux session.

Observed conditions

1. Start Codex app-server processes from an interactive macOS session.
2. Allow their original owner/session to exit while the servers remain alive.
3. The processes become detached, have no TTY, and are reparented to PID 1.
4. Attempt an OAuth login or credential persistence operation.
5. Keychain denies interaction and the app-servers repeatedly retry.

Expected behavior

• App-server lifecycle should remain tied to an explicit owner or durable
  service context.
• A noninteractive Keychain failure should produce one actionable typed error
  with bounded retry/backoff.
• OAuth persistence requiring user interaction should be routed through the
  logged-in GUI context or deferred explicitly.
• Detached servers without clients should not retry Keychain access every
  second.

This may be adjacent to #33540, but this report concerns detached app-server
lifecycle and noninteractive macOS Keychain access rather than refresh-token
serialization.

Start with the app-server lifecycle and OAuth login or credential-persistence path described in the report, reproducing the detached, no-TTY condition on macOS. Trace the repeated Keychain failures and determine how stale servers are handled. Done means detached servers avoid unbounded retries and noninteractive failures produce an actionable bounded response.