Aha! Now I know that nvm was slowing my shell startup down. Now I've reconfigured .zshrc to lazy-load nvm, and everything's snappy:
zstyle ':omz:plugins:nvm' lazy yes zstyle ':omz:plugins:nvm' lazy yeshttps://github.com/lukechilds/zsh-nvm?tab=readme-ov-file#laz...