Side conversation Ctrl+C return does not exit when pet mode is enabled

Summary

In a Codex side conversation, the banner says Side from main thread · Ctrl+C to return, but pressing Ctrl+C does not return to the main thread. Sending /exit is treated as a normal chat message rather than an exit command.

This was observed with pet mode enabled in config, so pet/key handling may be related, but I do not have direct proof that pet mode is the root cause.

Environment

• Codex CLI: codex-cli 0.135.0
• OS: macOS 26.3.1 (25D771280a), darwin arm64
• Local config: [tui] pet = "codex"
• Surface: Codex side conversation / app-local workflow
• Project cwd: /Users/gyusupsim/Projects/retention_corp/paid-social-playbook

Steps observed

1. Start from a main Codex thread.
2. Enter a side conversation.
3. Observe the header: Side from main thread · Ctrl+C to return.
4. Press Ctrl+C.
5. Try /exit as a fallback.

Expected behavior

Ctrl+C should close/leave the side conversation and return to the main thread, or a documented fallback command should work.

Actual behavior

The side conversation remains active. /exit is delivered as a normal message instead of being intercepted as a control command.

Notes

• Config has pet = "codex" enabled, which may affect TUI focus/key handling, but this is only a hypothesis.
• I searched for existing issues with side conversation Ctrl+C, pet Ctrl+C, and Side from main thread; I found related /side bugs but not this specific exit failure.
• Current workaround is to open a new terminal and resume the target session from the project directory, for example:

cd /Users/gyusupsim/Projects/retention_corp/paid-social-playbook
codex resume