Local data
The app keeps the revocable session, preferences, bounded queue history, and resumable upload state needed for desktop operation. It should not store your Astral password.
Sign out locally
Use Sign out in the Windows app to remove its local session. Clear completed history separately if you also want to remove local filenames from the app.
Revoke remotely
If the device is lost, open Account from another browser and revoke that desktop session or all sessions.