fix(server): background server updates back off and stage one release at a time

A refused handoff retried the preflight every 30 seconds; it now waits for
the next hourly release check. Newer releases are not downloaded while one is
staged, so a long-closed update window cannot fill the disk. A ps fallback
after a failed native process snapshot no longer marks every terminal busy.
27c2d3d034maria-rcks committed on 10/10/2026, 12:27:36 AMparentd45968c
2 files changedLine totals unavailable