Redo frontend and dockerfile to use nginx and build in stages based on prod steps in romm

supervisor/frontend.conf

@@ -1,12 +1,12 @@
 [program:frontend]
 priority=50
-directory=/app/code/frontend
-environment=HOME=/app/code
-command=npm run dev
-user=cloudron
+directory=/tmp
+command=/usr/sbin/nginx -g "daemon off;"
+user=root
 autostart=true
 autorestart=true
 stdout_logfile=/dev/stdout
 stdout_logfile_maxbytes=0
 stderr_logfile=/dev/stderr
 stderr_logfile_maxbytes=0
+