ensure `NODE_BINARY` exists during Xcode build time

xcode-node-path-fnm.sh

# From discussion in schniz/fnm
# https://github.com/Schniz/fnm/issues/475#issuecomment-2672700307
# original author @erkie (https://github.com/erkie)

# No node? Try to load via fnm
if ! command -v node &> /dev/null; then
  output=$(zsh -l -c 'source ~/.profile; source ~/.zshrc; eval "$(fnm env --shell=zsh)" && fnm env')
  eval "$output"

  # if no node is found throw an error
  if ! command -v node &> /dev/null; then
      echo "Node could not be found: $SHELL $USER $HOME"
      exit 1
  fi
fi

export NODE_BINARY="$(realpath $(which node))"