Ship systemd/screencast-receiver.service, a template the install
script substitutes (binary path, run user) and enables so the
receiver starts at boot after the network and avahi-daemon, with
restart-on-failure and a raised start limit for slow-booting boards.
SIGTERM gives the graceful shutdown that withdraws the mDNS
announcement — systemctl stop never triggers the stale-record trap
that kill -9 does. Headless consoles render via KMSDRM (the script
adds the run user to video/render/input); desktop autologin sessions
uncomment two documented Environment lines.
The install script gains SC_RECEIVER_SERVICE=0 to opt out.
Validated: systemd-analyze verify on the substituted unit (only the
expected missing /usr/local/bin path on this dev machine), and a live
lifecycle test as a user unit: the service-managed receiver announced
itself (--discover found it), systemctl stop produced a clean exit
(Result=success, no restart) and the mDNS announcement was withdrawn
immediately.
