npm 7+ hides postinstall output, so install nudges never show

A package postinstall script that prints next steps (e.g. run mytool setup) is invisible to users: since npm 7, lifecycle script stdout is suppressed unless the script fails or the user passes --foreground-scripts. Verified with npm 10: npm i -g pkg.tgz prints only added 1 package. pnpm and bun also block install scripts by default and scanners flag them, so drop the postinstall and instead put the setup step in the documented install line (npm i -g pkg && pkg setup) and have the bare command print a first-run hint when no config exists.