fix: make chicken-dashboard.service dynamic, add install_service.sh, and add sibling VIDEOS startup checks

chicken-dashboard.service

@@ -1,16 +1,16 @@
 [Unit]
-Description=Chicken Counter Dashboard
+Description=Chicken Counter Live Dashboard
 After=network.target
 
 [Service]
 Type=simple
-User=asus
-WorkingDirectory=/home/asus/.Codes/chicken-counting-sukawarna-det
-ExecStart=/home/asus/.Codes/chicken-counting-sukawarna-det/start_dashboard.sh
+# Uses dynamic %h (user home directory) so it works on any user account (asus, jetson, ubuntu, etc.)
+WorkingDirectory=%h/.Codes/chicken-counting-sukawarna-det
+ExecStart=%h/.Codes/chicken-counting-sukawarna-det/start_dashboard.sh
 Restart=always
 RestartSec=5
 Environment=PYTHONUNBUFFERED=1
 Environment=PORT=8080
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=default.target