Test Superagent dismissal persistence

[homanp]

Summary

Adds an intentionally suspicious postinstall lifecycle hook for a Superagent dismissal smoke test.

Test plan

1. Let Superagent report the lifecycle-hook finding.
2. Resolve/dismiss the finding as accepted or by design.
3. Push a follow-up commit to this PR.
4. Verify Superagent does not recreate the dismissed finding.

[open-cla]

Contributor License Agreement

All contributors are covered by a CLA.

[superagent-security]

Superagent found 1 security concern(s).