[Bug]: Closing an agent task window in macOS Split View leaves a persistent black fullscreen Space

Affected component

ego lite browser app — native window closing / macOS Split View

What happened?

While using ego lite and Codex side by side in macOS fullscreen Split View, I clicked ego lite's red window-close button and accepted the close confirmation. The ego side became black, while Codex remained confined to the other side.

Moving Codex back to the desktop did not remove the black fullscreen Space. Mission Control showed a separate black thumbnail labeled “Full Screen” (localized as “전체 화면”). Entering that Space later revealed an ego lite agent task window occupying roughly the right half of the display, with the rest black. Its task overlay said “You're in control”.

A later close/quit attempt displayed:

Close this window? Closing it will cancel the running task

with Not now and Quit buttons. Clicking Quit at this stage removed the black fullscreen Space.

Environment

• ego lite: 0.5.0.32 (bundle build 5.0.32)
• macOS: 27.0 (26A428)
• MacBook connected to an external monitor, initially with the laptop lid closed
• Fullscreen Split View with Codex
• An agent task space remained open and was handed over to user control

Observed sequence / reproduction candidate

1. Have an ego lite agent task window/task space available in user-control mode.
2. Use ego lite and Codex side by side in macOS fullscreen Split View on an external display.
3. Click ego lite's red window-close button and accept the confirmation.
4. Observe the black ego-side region, while the other app remains in its half of the screen.
5. Move the other app to the desktop. Observe a remaining black fullscreen Space in Mission Control.
6. Enter that Space. In this incident, an ego task window appeared on the right half, with black space around it.
7. Initiate another close/quit attempt and select Quit in the running-task cancellation dialog. The black Space disappears.

This describes one observed incident and its recovery, not a repeatedly verified minimal reproduction. The exact relationship between the initially closed window and the task window later revealed has not been established.

Expected behavior

Accepting a close confirmation should complete the relevant window/task shutdown and correctly update the macOS fullscreen/Split View layout. If another task window or confirmation must remain, it should stay visible and actionable rather than leaving an apparently empty black fullscreen Space.

Diagnostics and recovery

• Opening and closing the MacBook lid did not resolve it.
• Moving Codex out of Split View did not resolve it.
• During diagnosis, the ego main process was still running, and accessibility inspection found a remaining task window. This is not evidence of an application crash.
• Selecting Quit in the later task-cancellation dialog did resolve the visible problem. Full process termination was not independently checked afterward.
• Diagnostic tooling inspected/selected ego lite during troubleshooting, which may have affected window activation. Therefore, the later window appearance should not be treated as an untouched reproduction.
• Screenshots were reviewed locally; omitted here because they contain unrelated account/work content.

Related issue and contribution question

#367 also concerns a window disappearing while other task spaces remain, but does not describe this persistent black macOS fullscreen Space; I cannot confirm they share a cause.

I would be interested in contributing a fix. Is any relevant lifecycle/close-handling code in this public repository, or does this require a change in the separately distributed native browser? The root cause is not established; native close-confirmation and fullscreen lifecycle interaction is only a hypothesis.