chore(release): rename npm wrapper to nodeup-cli

[dipto0321]

Summary

Renames the npm wrapper from nodeup to nodeup-cli because
the bare nodeup name on npmjs.com is owned by an unrelated,
dormant 2015 package (romanmt/nodeup — "a simple cluster
implementation for node"). npmjs.com does not allow publishing
under an existing name, so we ship under nodeup-cli instead.
The downloaded binary still installs as the nodeup CLI on
$PATH — only the npm package name changed, not the brand,
not the binary, not the release pipeline.

Why nodeup-cli vs nodeupgrader / @dipto0321/nodeup / others:

• nodeup-cli keeps the nodeup brand token visible
• the -cli suffix matches the npm convention for a CLI tool when
  the bare name is taken (eslint-cli, tsc-cli, http-server-cli)
• it's unscoped (better search discoverability than @scope/nodeup)
• all strong alternatives were probed via npm view first; many
  are taken, the rest are noisier

Linked issues

Refs #35 (the existing tracking issue for the manual npm publish
step). Issue body needs an addendum noting the rename.

Type of change

• feat — new feature (MINOR bump)
• fix — bug fix (PATCH bump)
• refactor — no behavior change
• chore — distribution channel rename
• docs — documentation only
• ci — CI/CD only
• build — build system only
• Breaking change (MAJOR bump) — explain below

Note on "breaking": the wrapper has not yet been published to
npmjs.com, so there are no users to break. After this PR merges,
the very first npm publish lands under nodeup-cli and that's
the install name from day one.

Checklist

• Title follows Conventional Commits (chore(release): subject)
• I ran make ci locally — build + test + vet pass
• I added or updated tests — N/A (package rename in package.json
  + docs; behavior identical)
• I updated relevant docs (README, docs/installation.md,
  docs/release-checklist.md, nodeup-npm/README.md)
• No new linter warnings
• If breaking: documented migration path — N/A, not breaking

Scope notes / things reviewers may want to look at

• Verified packaging. npm pack --dry-run from nodeup-npm/
  now produces nodeup-cli-1.0.0.tgz with the same 5 files as
  before (LICENSE, README.md, package.json, scripts/check.js,
  scripts/install.js). Same archive layout, same install hook,
  just name: "nodeup-cli" in package.json.
• install.js is unchanged. The script's user-agent header
  still says nodeup-npm-wrapper and the binary still installs to
  bin/nodeup — the binary name on disk and on $PATH is still
  nodeup. Only the npm package name changed.
• Stale nodeup.md and .puku/plans/*.md also reference
  npm install -g nodeup, but both are gitignored (scratch /
  design docs) and don't ship. Not touched.
• Tracking issue Release prep: publish nodeup-npm to npm registry on v1.0.0 cut #35 still tracks the npm publish step but
  now references nodeup-cli after this rename. I'll add a comment
  to Release prep: publish nodeup-npm to npm registry on v1.0.0 cut #35 after this PR merges.

Screenshots / output

$ cd nodeup-npm && npm pack --dry-run
npm notice 📦  nodeup-cli@1.0.0
npm notice Tarball Contents
npm notice 1.1kB LICENSE
npm notice 3.7kB README.md
npm notice 944B package.json
npm notice 1.9kB scripts/check.js
npm notice 6.9kB scripts/install.js
npm notice total files: 5

[cocogitto-bot]

✔️ 441a2ab - Conventional commits check succeeded.