feat: point the fleet at wss LiveKit room uwh-telhai

Publish and subscribe over wss://livekit.uni-wh.de:7800 and refuse
cleartext ws://. Conference room is uwh-telhai. Includes the uncommitted
encoded H.264 publish path, Rally hairpin, and KMS wall overlay.

deploy/99-rally-pin.rules

@@ -0,0 +1,10 @@
+# Logitech Rally / Rally Bar as the speaker camera (not a cam-NN C920 slot).
+# Product ids: Rally Camera 0881, Rally Bar Huddle 087c, Rally Bar 089b,
+# Rally Bar Mini 08d3. Install when the device is on site:
+#   cp deploy/99-rally-pin.rules /etc/udev/rules.d/
+#   udevadm control --reload-rules && udevadm trigger
+#
+SUBSYSTEM=="video4linux", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="0881", ATTR{index}=="0", SYMLINK+="rally"
+SUBSYSTEM=="video4linux", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="087c", ATTR{index}=="0", SYMLINK+="rally"
+SUBSYSTEM=="video4linux", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="089b", ATTR{index}=="0", SYMLINK+="rally"
+SUBSYSTEM=="video4linux", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="08d3", ATTR{index}=="0", SYMLINK+="rally"

deploy/livekit-cameras.service

@@ -1,11 +1,9 @@
 [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
+After=network-online.target sound.target
 Wants=network-online.target
-# 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
+# Local livekit-server is disabled; publishers use LIVEKIT_URL in .env.
 
 [Service]
 Type=simple

deploy/livekit-displays.service

@@ -1,8 +1,10 @@
 [Unit]
 Description=Drive 3 DRM displays with LiveKit camera output (GStreamer kmssink)
 Documentation=file:///home/fdenkena/livekit-cameras/README.md
-After=network-online.target livekit-server.service livekit-cameras.service
-Wants=network-online.target livekit-cameras.service
+After=network-online.target
+Wants=network-online.target
+# Do not After=/Wants= livekit-cameras: the wall must stay up when cameras
+# are missing and when the SFU is down (on-screen error, then reconnect).
 
 [Service]
 Type=simple
@@ -10,7 +12,7 @@ WorkingDirectory=/home/fdenkena/livekit-cameras
 EnvironmentFile=-/home/fdenkena/livekit-cameras/.env
 Environment=PYTHONUNBUFFERED=1
 # Exclusive KMS access — no X/Wayland on these connectors.
-ExecStartPre=/home/fdenkena/livekit-cameras/deploy/wait-for-livekit.sh
+# Start kmssink immediately; run_displays.py shows LiveKit errors on the wall.
 ExecStart=/home/fdenkena/livekit-cameras/.venv/bin/python /home/fdenkena/livekit-cameras/run_displays.py
 ExecStop=/bin/kill -TERM $MAINPID
 Restart=always

deploy/wait-for-livekit.sh

@@ -2,6 +2,9 @@
 # Wait until LIVEKIT_URL (from .env) accepts TCP. Used so publishers do not
 # race the local test livekit-server on boot. When LIVEKIT_URL points at a
 # remote host this waits on that host instead.
+#
+# bash /dev/tcp to an unreachable host can hang until the kernel SYN timeout
+# (longer than systemd TimeoutStartSec). Cap each probe at 1s.
 set -u
 ENV_FILE=/home/fdenkena/livekit-cameras/.env
 if [ -f "$ENV_FILE" ]; then
@@ -29,7 +32,7 @@ if [ "$host" = "localhost" ]; then
 fi
 echo "wait-for-livekit: $host:$port"
 for _ in $(seq 1 30); do
-  if (echo >/dev/tcp/"$host"/"$port") 2>/dev/null; then
+  if timeout 1 bash -c "echo >/dev/tcp/${host}/${port}" 2>/dev/null; then
     echo "wait-for-livekit: ready"
     exit 0
   fi