detach long-running background processes from autostart service cgroup

KDE Plasma runs each autostart .desktop entry as a systemd user unit.
systemd tracks service liveness by cgroup membership, not just the
main PID. Any process forked inside the service — even via setsid or &
— stays in the service's cgroup and keeps app-logon_script.sh@autostart
in active (running) state indefinitely after logon_script.sh exits.

mount_ecrypt_home.sh: wrap the gocryptfs mount call with
  systemd-run --user --scope --unit=gocryptfs-home
The FUSE daemon that gocryptfs forks now lives in its own transient
scope cgroup. Exit-code propagation is unchanged because systemd-run
--scope returns the main process's exit code.

0050_nextcloud_desktopclient/user_run.sh: replace
  /usr/bin/setsid ... &
with
  systemd-run --user --scope --unit=nextcloud-client ... &
setsid creates a new session but does not move the process out of the
cgroup; systemd-run --scope does.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client_software/0050_nextcloud_desktopclient/user_run.sh

@@ -151,7 +151,7 @@ done
 #fi
 # Now start Nextcloud
 echo "Starting Nextcloud Client in Background"
-/usr/bin/setsid ${BASECMD} >${TEMPDIR}/nc_desktop_client.log 2>&1 &
+systemd-run --user --scope --unit=nextcloud-client ${BASECMD} >${TEMPDIR}/nc_desktop_client.log 2>&1 &
 sleep 2
 echo "Done Setup of Nextcloud."
 exit 0