[Bug] Closing an Alt+O pop-out terminal removes an inline swarm worker and aborts its task

Summary

With agents.swarm_spawn_mode = "inline", pressing Alt+O on a running swarm worker opens that worker in a separate terminal. Closing the pop-out terminal removes the worker from the swarm and aborts its running task.

Based on the current UI contract and source comments, this appears to be a bug rather than intentional behavior. The UI calls the action open / pop out; it does not indicate that the new terminal takes ownership of the worker lifecycle or that closing it is destructive.

If this behavior is intentional, the missing destructive warning is still a UX bug. For an inline worker that was already server-managed before the pop-out, keeping the worker alive after the viewer disconnects seems more consistent with both inline and pop out semantics.

Environment

• Jcode: v0.80.1 (59aaacc)
• OS: Windows 11
• Configuration:

[agents]
swarm_spawn_mode = "inline"
swarm_strip_layout = "vertical"

The relevant Alt+O and disconnect-cleanup paths are still present on the current upstream master.

Steps to reproduce

1. Start a Jcode session.
2. Spawn an inline swarm worker with a task that runs long enough to inspect.
3. Press Alt+N to focus the swarm panel.
4. Select the running worker with Alt+Up / Alt+Down.
5. Press Alt+O to open the worker in a new terminal.
6. Close that terminal before the worker completes.
7. Return to the coordinator and inspect the swarm panel/task state.

Actual behavior

• The worker disappears from the swarm panel.
• The worker is removed from swarm membership.
• Its running task is aborted.
• The coordinator can no longer await its normal completion/report.

Expected behavior

Closing an Alt+O viewer for an inline worker should:

• disconnect only that terminal client;
• keep the inline worker running on the server;
• retain its swarm membership and plan participation;
• not abort the active task;
• allow it to report completion to the coordinator normally.

Source analysis

Alt+O calls spawn_resume_in_new_terminal from:

crates/jcode-tui/src/tui/app/tui_state.rs
pop_out_selected_swarm_agent()

The inline worker was originally created as an in-process/headless worker in:

crates/jcode-app-core/src/server/comm_session.rs
spawn_swarm_agent()

The pop-out reuses the ordinary --resume <session_id> path without identifying the connection as a temporary attachment, observer, or detachable viewer.

When the pop-out terminal exits, the shared disconnect path runs:

crates/jcode-app-core/src/server/client_disconnect_cleanup.rs
cleanup_client_connection()

With no successor client attached, it performs destructive cleanup, including the equivalents of:

remove_session_entry(...)
members.remove(client_session_id)
remove_session_from_swarm(...)
processing_task.take().abort()

This makes a viewer connection the effective lifecycle owner of a worker that was previously server-managed.

Platform scope

The issue has been observed on Windows.

The session attach and disconnect cleanup paths are shared cross-platform and do not contain a Windows-specific branch for this behavior. macOS and Linux therefore appear likely to behave the same way once the spawned jcode --resume client actually exits, but that is source-based inference and has not been reproduced there yet.

Suggested direction

Give Alt+O pop-outs for inline workers an explicit non-owning connection mode, such as observer or detachable.

On disconnect, that mode should unregister only the client connection/event sender and should not:

• remove the worker from sessions;
• remove the swarm member;
• call remove_session_from_swarm();
• abort the worker's active task.

Visible workers whose terminal intentionally owns their lifecycle can retain the current behavior.

Workaround

Keep the Alt+O terminal open (or minimized) until the worker finishes. The Alt+N panel is not a full replacement because it mainly shows status/Todos and only a transient tail of in-progress assistant text, not the complete worker transcript or tool output.

Start with pop_out_selected_swarm_agent() in crates/jcode-tui/src/tui/app/tui_state.rs, then trace spawn_swarm_agent() in crates/jcode-app-core/src/server/comm_session.rs and cleanup_client_connection() in crates/jcode-app-core/src/server/client_disconnect_cleanup.rs. Reproduce the Alt+O workflow and inspect disconnect handling; done means closing the viewer leaves the inline worker, swarm membership, and active task intact until normal completion.