BAD CODE™: stop release preflight from rerunning the full test corpus through prepack

[flyingrobots]

Problem

scripts/release-preflight.sh runs the coverage suite explicitly and then calls npm pack --dry-run. npm invokes the package prepack lifecycle for that dry-run, and prepack currently reruns build, lint, test:local, and consumer typechecking. A successful release preflight therefore repeats expensive gates that already ran in the same command and in CI.

Evidence

• scripts/release-preflight.sh runs npm run test:coverage:ci before its pack phase.
• The pack phase calls npm pack --dry-run without suppressing lifecycle scripts.
• package.json defines prepack as build + lint + test:local + consumer typechecking.
• PR Make v18-to-v19 migration safe and observable #825's release preflight took about ten minutes and visibly reran the unit corpus during packaging.

Desired outcome

• Preserve a safe npm publish and manual npm pack lifecycle gate.
• Give the release preflight an explicit artifact-build path that does not rerun gates already proven in the same invocation.
• Keep the packed-artifact smoke and package-content verification intact.
• Add executable coverage that proves release preflight invokes each expensive gate at most once.
• Document which command owns validation versus artifact construction so future lifecycle changes cannot reintroduce the duplication.

Dependency posture

This is follow-up release-tooling debt, not a v19.0.1 migration blocker. Schedule it after the current migration-guidance milestone closes.

[coderabbitai]

🔗 Related PRs

#676 - release: repair v18.1.1 autotag link gate [merged]
#687 - docs: formalize Continuum release contract [merged]
#698 - Fix: make release guards consume release profile [merged]
#801 - Gate v19 on migrated retained-read speed [merged]
#825 - Make v18-to-v19 migration safe and observable [open]

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