[Pepps233]

Summary

Improve npm/pnpm self-update feedback and recovery.

Reasoning

Show progress without hiding warnings, and provide targeted recovery instructions instead of blanket cache deletion.

Changes

• Add a compact terminal activity display and preserve redirected logs.
• Explain permission, Node-version, registry, integrity, and interrupted-install failures.
• Check the Node.js requirement before initializing CLI dependencies.

Testing

• Update, runtime-check, package-command, and config tests passed.
• npm run check and ./test.sh passed locally.
• Inspected the activity display in tmux.