Fix Warp notifications for detached Codex hooks

[seemeroland]

Restore Warp lifecycle notifications when Codex runs hooks without a controlling terminal. Codex 0.155.0 introduced terminal detachment, so the previous /dev/tty-only notifier could silently drop in-progress and completion updates even while prompts executed successfully.

What changed

• Keep /dev/tty as the first choice for compatibility with older Codex versions.
• Fall back to a terminal device found through bounded process-ancestry discovery. Linux uses /proc and readlink, including minimal images without ps; macOS uses ps.
• Emit a nonfatal diagnostic when no writable terminal is found. Notification payloads and the Windows transport are unchanged.
• Add isolated pseudo-terminal regression tests and document local container testing.

This does not change plugin version metadata or the minimum-version pins in Warp. Existing cached installations need an explicit refresh; release rollout is separate.

Validation

Manually tested with e2e tests and oz-local:

• On codex 0.144 with this plugin, codex updates state through hooks properly (backward compatibility)
• On codex 0.159.0 with this plugin, codex updates state through hooks properly (what this change fixes)
• On codex 0.159.0 without this plugin, codex fails to update state through hooks

Completed during implementation:

• Five notification tests passed in a disposable Linux container, including inherited-session and detached-hook cases and actual lifecycle hook scripts.
• Existing shell suites passed: 65 hook/manifest assertions and 10 factory-files assertions.
• Restoring the old notifier in a temporary copy made the detached-hook regression fail as expected.
• Bash syntax and whitespace checks passed.

macOS PTY integration remains unverified: an isolated probe also hung without the plugin involved. Windows transport was not changed and PowerShell tests were not run locally.

Upstream behavior change: openai/codex#43876

CHANGELOG-APP: Fixed missing Codex status notifications when hooks run without a controlling terminal.

Agent conversation

Co-Authored-By: Warp agent@warp.dev