Greptile Summary

This PR extends the prebuilt binary release pipeline to include a native Linux ARM64 package (hunkdiff-linux-arm64), enabling users running on Linux aarch64 (e.g. Lima VMs on Apple Silicon) to consume a prebuilt binary rather than building from source.

The change touches all three layers consistently:

• Workflow (.github/workflows/release-prebuilt-npm.yml): adds a new matrix entry using the ubuntu-24.04-arm GitHub-hosted runner, which natively produces the ARM64 artifact without any cross-compilation.
• Package helpers (scripts/prebuilt-package-helpers.ts): inserts the new PlatformPackageSpec into PLATFORM_PACKAGE_MATRIX in alphabetical order, so all existing generic lookup / staging / publish scripts pick it up automatically with zero further changes.
• Tests (test/prebuilt-package-helpers.test.ts): correctly flips the linux/arm64 resolution from an expected throw to a successful lookup, and adds the new package name to the stable sort expectation.

No behaviour changes for existing platforms; this is a pure additive extension.

Confidence Score: 5/5

• This PR is safe to merge — it is a minimal, additive change with no risk to existing platform builds.
• All three changed files are in perfect sync: the workflow adds the native ARM64 runner, the helper matrix gains the matching spec, and the tests are updated to reflect the new expected behaviour. The change is purely additive, all existing matrix entries are untouched, and the generic downstream scripts (stage, publish, GitHub release) consume PLATFORM_PACKAGE_MATRIX dynamically so they automatically gain ARM64 support without modification.
• No files require special attention.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    T[Tag push / workflow_dispatch] --> M[build-binaries matrix]

    M --> J1[hunkdiff-darwin-arm64\nmacos-14]
    M --> J2[hunkdiff-darwin-x64\nmacos-15-intel]
    M --> J3[hunkdiff-linux-x64\nubuntu-latest]
    M --> J4[hunkdiff-linux-arm64\nubuntu-24.04-arm\n🆕 NEW]

    J1 & J2 & J3 & J4 --> SR[stage-release\nubuntu-latest]
    SR --> PUB[publish\nubuntu-latest]
    PUB --> GHR[create-github-release]

_{Reviews (1): Last reviewed commit: "build: add linux arm64 prebuilt package ..." | Re-trigger Greptile}

@aliou Thanks - yep just an oversight.