chore: track npm CLI beta 0.0.4 release

[jiashuoz]

Summary

• Carry forward the already-published, reviewed npm wrapper from Publish Rainier CLI beta via npm #52 with no runtime changes.
• Pin package version 0.0.4 to four immutable v0.0.4 CLI archives and binary hashes; update installation/help documentation and expose make npm-test.
• CLI binaries are built from main commit 70a3736, tagged v0.0.4. This PR only tracks npm distribution sources; no Go or cloud implementation changes.

Verification

• Full make verify passed, including Go tests, builds, public-contract checks, and vet.
• Fresh CLI/readiness/attach race tests passed.
• All 11 npm tests passed on macOS ARM64 and Linux ARM64/x64 with Node 22.
• All four native binaries report rainier v0.0.4 (Intel macOS through Rosetta, Linux x64 through local emulation).
• All archive/binary SHA-256 pins match; npm tarball includes exactly six allowlisted files, no dependencies or lifecycle scripts.
• npm publish dry-run passed with explicit beta tag. Final public-download verification follows publication.

Scope

No cloud deployment, shared VM testing, or environment publication. Existing npm PR #52 remains untouched; this branch contains the current release wrapper based on fresh origin/main.

[jiashuoz]

Release artifact verification: all seven downloaded GitHub assets match the uploaded files byte-for-byte, and all SHA-256 checks pass. GitHub prerelease v0.0.4 is now public; its annotated tag resolves to 70a3736. Fresh packed npx and isolated global installs downloaded and ran the public macOS ARM64 binary; Linux ARM64/x64 Node 22 packed installs also downloaded, verified, and ran the matching public binaries. Cached macOS execution passed with the downloader network disabled. npm publication is pending account-holder browser authentication; no cloud resources were changed.

[jiashuoz]

Published successfully: @tokencanopy/rainier@0.0.4 is available on npm, beta=0.0.4 and latest=0.0.3. A fresh public-registry package-name npx invocation downloads and runs rainier v0.0.4, and focused doctor help works. The registry tarball matches the tested artifact byte-for-byte (SHA-1 b321c834799ca4c8b34aa57aad4e672d8976ebe0). GitHub prerelease: https://github.com/tokencanopy/rainier/releases/tag/v0.0.4 . Package: https://www.npmjs.com/package/@tokencanopy/rainier/v/0.0.4 . CLI source tag points to merged main; this PR remains open to track the npm wrapper sources. No cloud deployment or environment publication was performed.