ops: appliance boot — wait for cameras/LiveKit, power button powers off

deploy/livekit-cameras.service

@@ -1,20 +1,28 @@
 [Unit]
 Description=Publish C920 cameras (speechbrain audio) to LiveKit
+Documentation=file:///home/fdenkena/livekit-cameras/README.md
 After=network-online.target sound.target livekit-server.service
 Wants=network-online.target
-Requires=livekit-server.service
+# Wants, not Requires: local livekit-server is a test stand-in.
+# Point LIVEKIT_URL at a remote server later and you can disable this unit.
+Wants=livekit-server.service
 
 [Service]
 Type=simple
 WorkingDirectory=/home/fdenkena/livekit-cameras
+EnvironmentFile=-/home/fdenkena/livekit-cameras/.env
+Environment=PYTHONUNBUFFERED=1
+Environment=ENHANCE_MODE=force
+ExecStartPre=/home/fdenkena/livekit-cameras/deploy/wait-for-cameras.sh
+ExecStartPre=/home/fdenkena/livekit-cameras/deploy/wait-for-livekit.sh
 ExecStart=/home/fdenkena/livekit-cameras/.venv/bin/python /home/fdenkena/livekit-cameras/run.py
+ExecStop=/bin/kill -TERM $MAINPID
 Restart=always
 RestartSec=5
+TimeoutStartSec=90
 TimeoutStopSec=30
 KillMode=control-group
-Environment=PYTHONUNBUFFERED=1
-Environment=LIVEKIT_URL=ws://127.0.0.1:7880
-Environment=ENHANCE_MODE=force
+KillSignal=SIGTERM
 
 [Install]
 WantedBy=multi-user.target