Add security and community standard documentation

[rishabh3562]

Summary

The repository is missing key documentation for security and community standards. We need to add the following files:

• SECURITY.md – Guidelines for reporting vulnerabilities and best practices.
• CODE_OF_CONDUCT.md – Expected behavior for community members.
• CODEOWNERS – File ownership and automatic reviewer assignments.

Note: CONTRIBUTING.md already exists and does not need to be added.

Objectives

1. Security

   • Add SECURITY.md detailing how to report vulnerabilities securely.
   • Include supported versions and security best practices.

2. Community Standards

   • Add CODE_OF_CONDUCT.md outlining acceptable behavior and reporting.

3. Repository Management

   • Add CODEOWNERS to assign automatic reviewers for files and directories.

Acceptance Criteria

• SECURITY.md added and complete.
• CODE_OF_CONDUCT.md added and complete.
• CODEOWNERS added with correct maintainers.
• All files follow professional, standard formatting.