Repo had no vulnerability-reporting policy. Adds contact address,
response process, and a version-support statement scoped to the
current latest release (v3.2.1).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T65wWn7QeSKZMFoUCeyXCK
