Small refactor of user/groups and add checks during startup. Only use -x in bash scripts when DEBUG=true set in env vars

docker/rootfs/etc/s6-overlay/s6-rc.d/frontend/run

@@ -8,14 +8,14 @@ set -e
 if [ "$DEVELOPMENT" = 'true' ]; then
 	. /bin/common.sh
 	cd /app/frontend || exit 1
-	HOME=/tmp/npmuserhome
+	HOME=$NPMHOME
 	export HOME
 	mkdir -p /app/frontend/dist
 	chown -R "$PUID:$PGID" /app/frontend/dist
 
 	log_info 'Starting frontend ...'
-	s6-setuidgid npmuser yarn install
-	exec s6-setuidgid npmuser yarn watch
+	s6-setuidgid "$PUID:$PGID" yarn install
+	exec s6-setuidgid "$PUID:$PGID" yarn watch
 else
 	exit 0
 fi