Desktop Client: graceful shutdown during active Editor Session

[messiwu]

Parent

#112 — PRD: macOS Desktop Client (Electron, Intel x64 v1)

What to build

Extend Desktop Client lifecycle so quitting during an active Editor Session (SSE stream in progress, Coding Agent child running) aborts cleanly: in-flight conversion is cancelled, agent child processes are not left running, and the embedded server still shuts down.

End-to-end outcome: start generation → quit app mid-stream → no orphan agent CLI processes; relaunching works normally.

Acceptance criteria

• Quit (menu, ⌘Q, or documented window-close behavior) aborts in-flight /api/convert SSE streams
• No surviving Coding Agent child processes after quit during active generation (manual verification with at least one real agent CLI)
• Embedded Node server still terminates on quit
• Relaunch after abort shows a healthy editor; no port-bind failures from leaked processes
• Automated test where feasible (supervisor shutdown while mock long-running child is active)

Blocked by

• Desktop Client: MVP Electron window + process supervisor #114

[lefarcen]

Hi @messiwu! 👋

This is a well-scoped Desktop Client follow-up — especially the quit-mid-stream path, the no-orphan-agent requirement, and the relaunch health check.

I took a quick pass through the current web flow: /api/convert already threads request aborts into an AbortController, and the client-side convert hook already has a cancel path. So the desktop-specific gap looks less like the SSE route itself and more like making app quit propagate cleanly through the upcoming supervisor / child-process lifecycle once #114 lands.

Given that this is blocked by #114 and the desktop shell is still being added, I’m tracking this in the enhancement lane rather than calling a root cause yet. The acceptance criteria here are concrete and useful for the next implementation slice.