v1.6.6

Fixed

• Quitting from the tray icon while an update is installing no longer leaves you with no app at
  all. Applying an update starts the replacement daemon and shuts the old one down 800ms later.
  For that fraction of a second the replacement was a CHILD of the daemon on its way out, and the
  tray's Quit does not stop one process, it force-kills a whole process tree, so a Quit landing in
  that window killed both. Neither detached: true nor .unref() removes a child from its
  parent's tree on Windows, which is exactly why the shared launch helper exists; the relaunch
  simply never used it. Measured directly: with the old spawn the replacement dies to a
  tray-style tree-kill, with the new one it survives.
• The relaunch now survives Windows throwing away the environment. That launch helper hands
  the process off to Windows' own process-creation service, which does not pass on environment
  variables, and the port and the "you are the replacement" signal were both environment
  variables. Left as they were, the replacement would have bound a fresh port instead of taking
  over its predecessor's, stranding whatever tab you had open. Both now travel as command-line
  arguments, which that service does deliver, with the environment kept as a fallback for macOS
  and Linux.