systemd services: midi-bridge, pd-synth-onboard, led-matrix-viz + install script

system/pd-synth-onboard.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=Pure Data Synth (Onboard PMIC Audio)
+After=multi-user.target
+Wants=midi-bridge.service
+
+[Service]
+Type=simple
+User=arduino
+ExecStartPre=/bin/sh -c 'systemctl --user stop pipewire.socket pipewire.service wireplumber 2>/dev/null; sleep 0.5'
+ExecStart=/home/arduino/uno-q-audio-synth/scripts/start-synth.sh --onboard
+ExecStop=/usr/bin/killall pd
+WorkingDirectory=/home/arduino/uno-q-audio-synth
+Restart=on-failure
+RestartSec=3
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target