feat(npm): enrich @runner-run/* platform metadata for Socket Quality

[kjanat]

What

Bare @runner-run/* platform packages (the prebuilt-binary sub-packages npm selects via optionalDependencies) scored low on Socket.dev Quality: missing keywords, a thin description, and a ~5-line README. The facade package had full metadata; the sub-packages did not.

Changes

• platformPackageJson: add keywords (facade + prebuilt/binary/native/cli/task-runner + os/cpu/libc) and a real description.
• platformReadme: expand to a proper README (Do I install this?, Contents, More) explaining the optionalDependencies resolution and pointing at the facade.

Notes

• Build-script only; takes effect on the next release build. No version bump, npm/dist/ is generated.
• Generated description/README use plain punctuation (no em-dashes) since they ship to npm.
• Did not touch resolve.cjs (the #pkg swap only relocates the Socket URL alert, net-zero) or launch.cjs (heuristic AI-anomaly flag, owner-triage in the dashboard, not a code change).
• CHANGELOG updated. node --check + dprint check clean.

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR updates generated metadata for @runner-run/* platform packages. The build script now adds keywords and a richer package description, and it rewrites the generated README to describe the package contents and installation guidance. The changelog entry was updated to match the new metadata and npm’s platform-package selection via optionalDependencies.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

Arrr, the platform packages got a proper coat,
Keywords and descriptions now float the boat.
The README points landlubbers to the right shore,
And the changelog notes the haul with a tidy roar.
No stubby scraps left in the cargo hold, matey.

🚥 Pre-merge checks | ✅ 7 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Semver Version Bump Validation	⚠️ Warning	FAIL: npm/scripts/build-packages.ts changed, but Cargo.toml stays 0.14.2 on base and PR; no SemVer bump detected.	Bump the repo/package version in the appropriate manifest (for example Cargo.toml) to the next SemVer release, then re-run validation.

✅ Passed checks (7 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title is descriptive and matches the metadata and README enrichment work in the PR.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 30.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Changelog Update	✅ Passed	PASS — npm/scripts/build-packages.ts changed, and CHANGELOG.md adds an ## [Unreleased] → ### Changed entry describing the metadata/README update; no version bump.
Agents.Md Documentation Updated	✅ Passed	No AGENTS.md files exist anywhere in the repo, so there was nothing to update for these build-script and changelog changes.
Description check	✅ Passed	The description matches the metadata and README updates for the @runner-run platform packages, so it is clearly on topic.

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