fix(release): disable preflight package cache

[kattsushi]

Closes #268

Summary

• Disable actions/setup-node package-manager cache autodetection in the Node-only stable PREFLIGHT job.
• Prevent PREFLIGHT from requiring a pnpm executable before its read-only verifier can run.
• Add a release-policy mutation test for the exact setup contract.

Failure Evidence

Stable PREFLIGHT run https://github.com/devx-op/effectify/actions/runs/33354701870 failed before verification with:

Unable to locate executable file: pnpm.

The validate job succeeded; no stable tags, GitHub Releases, or npm versions were created.

Changes

File	Change
.github/workflows/release-stable.yml	Set package-manager-cache: false only on stable PREFLIGHT setup-node.
scripts/release-policy-contract.test.mjs	Require the Node-only PREFLIGHT bootstrap contract and reject a cache-enabled mutation.

Test Plan

• RED: release policy contract reported 5 failures for the missing PREFLIGHT cache guard.
• GREEN: node --test scripts/release-policy-contract.test.mjs — 30 passed, 0 failed.
• Independent verification: git diff --check passed.
• Confirmed PREPARE/FINALIZE setup-node configuration and permissions are unchanged.

Contributor Checklist

• Linked approved issue fix: complete Effect v4 cleanup and restore stable releases #268.
• Added exactly one type:* label: type:bug.
• Conventional commit; no co-author trailers.
• No npm publication occurs in this PR.

[coderabbitai]

Warning

Review limit reached

Next included review available in 26 seconds.

View limit details

Limit details: You’ve used the included review currently available.

You've used all free OSS reviews for now. Wait for the free limit to reset to keep reviewing this public repository.

Learn how review limits work.

Review configuration:

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: c8a3faea-e2be-424f-ab5c-626d1c36af03

📥 Commits

Reviewing files that changed from the base of the PR and between 31a6d45 and adb5a3a.

📒 Files selected for processing (2)

• .github/workflows/release-stable.yml
• scripts/release-policy-contract.test.mjs

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}