installer: require target user for system finalizer

install/config/docker.sh

@@ -1 +1 @@
-usermod -aG docker "${OMARCHY_INSTALL_USER:-${USER:-}}"
+usermod -aG docker "$OMARCHY_INSTALL_USER"

install/config/hardware/apple/fix-t2.sh

@@ -12,7 +12,7 @@ if lspci -nn | grep -q "106b:180[12]"; then
     tiny-dfr
 
   # Add user to video group (required for tiny-dfr to access /dev/dri devices)
-  usermod -aG video "${OMARCHY_INSTALL_USER:-${USER:-}}"
+  usermod -aG video "$OMARCHY_INSTALL_USER"
 
   # Enable T2 services
   systemctl enable t2fanrd.service

install/config/input-group.sh

@@ -1,2 +1,2 @@
 # Give this user privileged input access for dictation tools + xbox controllers to work
-usermod -aG input "${OMARCHY_INSTALL_USER:-${USER:-}}"
+usermod -aG input "$OMARCHY_INSTALL_USER"