Improve error message when Node.js < 18 is detected

[KD-K2N2]

Description

When a user has Node.js < 18, the error message could be more helpful.

Current

✗ Node.js v16.14.0 — requires >= 18
  Fix: Download from nodejs.org

Proposed

✗ Node.js v16.14.0 detected — Cortex requires Node.js 18 or later

  How to upgrade:
    macOS:   brew install node@22
    Linux:   curl -fsSL https://deb.nodesource.com/setup_22.x | sudo -E bash - && sudo apt install -y nodejs
    Windows: Download from https://nodejs.org/en/download
    nvm:     nvm install 22 && nvm use 22

  Current: v16.14.0
  Required: >= 18.0.0

Good first issue

Simple string change in packages/cli/src/index.ts — search for the Node version check.