docs: add SECURITY.md

[solardome]

This PR adds a basic SECURITY.md file for the repository.

It documents:

• the general support policy
• how to report security vulnerabilities privately
• what information to include in a report
• a simple disclosure process

This helps GitHub display the repository's security policy and gives users a clear path for reporting vulnerabilities responsibly.

---

Note

Low Risk
Low risk documentation-only change; no code paths, configuration, or runtime behavior are affected.

Overview
Adds a new SECURITY.md file so GitHub can display a security policy for the repository.

The document defines the supported version policy (latest major line), directs reporters to private vulnerability reporting, lists information to include in reports, and outlines a simple disclosure/triage process.

^{Reviewed by Cursor Bugbot for commit 4c3ab58. Bugbot is set up for automated code reviews on this repo. Configure here.}

[ofekshenawa]

@solardome Thank you for contributing this, the team will review it soon!