chore: check meets public repo requirements

[okramarenko]

No description provided.

[cursor]

PR Summary

Low Risk
Adds GitHub metadata and a path-filtered CI workflow only; no application or runtime behavior changes.

Overview
Adds the public release request metadata file (MIT license, business justification, and primary contact) required for open-sourcing.

Introduces a pull request workflow that runs only when .github/public-release-request.yml changes. It calls the shared singlestore/securitytesting public-readiness reusable workflow with contents: read and pull-requests: write so automated checks can run on the release request.

^{Reviewed by Cursor Bugbot for commit b19c526. Configure here.}