Desktop app: auto-archive completed scheduled-task (Routine) sessions

Problem

The desktop app's scheduled tasks ("Routines" in the sidebar) each spawn a new session per run. Completed runs remain as active sessions in the sidebar indefinitely; with four standing routines (three daily, one weekly) that is roughly 25-30 finished sessions per week to archive by hand. There is currently no setting to archive them automatically — the only bulk behavior today is that deleting a task archives all of the sessions it created.

Request

Either (or both) of:

• A per-task or global preference to auto-archive a routine's session when its run completes, analogous to the existing "Auto-archive on PR close" preference.
• A retention policy for routine-generated sessions, similar in spirit to cleanupPeriodDays for CLI sessions.

Workaround attempted

Ending the task's prompt with a self-archive step (the session-management archive_session tool with session_id: "self"). Whether its confirmation prompt can be satisfied in an unattended run is undocumented; I'm testing that now. Even if it works, a first-class setting would be clearer than per-task prompt surgery.

Environment

Claude Code desktop app, Windows 11 Pro.