Proposal: Ubuntu/Debian .deb packaging for the standalone CLI #517

Proposal

Add Ubuntu/Debian distribution support and a native dpkg-deb packager for the
standalone CLI. The change is complete and verified on a fork branch; the
repository's pull_request_creation_policy is collaborators_only, so this
issue is the submission path recommended by CONTRIBUTING.md.

Branch: feat/linux-deb-package in feuyeux/minimax-code
Compare: https://github.com/MiniMax-AI/minimax-code/compare/main...feuyeux:feat/linux-deb-package?expand=1
Commit: feuyeux@60b628e

What it adds

• a self-contained .deb built from the same compiled dist, dependency
  manifest, licenses and release.json receipt as the npm archive
• installs under /usr/lib/minimax-code, provides /usr/bin/mcode, and
  depends on a compatible system Node.js runtime instead of bundling one
• Depends is pinned to the Node.js ABI used at build time, because
  better-sqlite3 ships a native V8 addon (Node 24 build:
  nodejs (>= 24.2), nodejs (<< 25))
• exact runtime dependency versions are installed into the package, including
  native SQLite, so installation needs no network apart from Node.js
• Debian copyright, changelog.Debian.gz, md5sums; no maintainer scripts
• native dpkg-deb only; no new build dependency

Tooling:

• scripts/package-deb.mjs and scripts/verify-deb.mjs
• shared CLI staging between the npm archive and .deb packagers
• a deb verification profile (test:deb-tools, build, verify:deb)
• a Debian package CI workflow that builds, verifies and unpacks the package
  into a temporary dpkg root
• installation, removal and local build documentation

Validation on the fork branch

• pnpm verify (full): 15 gates passed, Linux, Node 24.19.0
• pnpm verify --profile deb: 3 gates passed on a clean tree
• produced minimax-code_0.6.5-1_amd64.deb and verified its control metadata,
  layout, symlinks, checksum, mcode --version/--help, SQLite query and
  ripgrep from the extracted package
• dpkg --root=<temp> --force-not-root --force-depends -i unpacked and
  configured the package; /usr/bin/mcode --version reported 0.6.5

Not run: arm64 packaging, a real privileged apt install, live MiniMax
services.

Question

Would maintainers prefer this as a PR from a collaborator, or should the
approach be adjusted first (for example, packaging into the existing release
workflow instead of a separate workflow)? I can also split the change further
if the CI/doc surface is broader than you want for a first contribution.