Issue Description

Add the OpenSSF Best Practices Passing badge to README.md to display the project's commitment to security and quality standards. The project has completed the OpenSSF Best Practices Badge self-certification questionnaire and should now display the earned badge.

Project ID: 11532
Badge Level: Passing (Silver badge deferred for future work)

Requirements:

1. Badge placement - Add in the Legal section of README.md alongside existing security reference
2. Logo sizing - Use native OpenSSF badge format for consistency with bestpractices.dev
3. Link target - Badge must link to https://www.bestpractices.dev/projects/11532

Badge format:

[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/11532/badge)](https://www.bestpractices.dev/projects/11532)

Acceptance criteria:

• OpenSSF Best Practices Passing badge displays on README.md
• Badge links to https://www.bestpractices.dev/projects/11532
• Badge renders correctly in GitHub markdown preview

Additional Context

The Passing badge criteria have been satisfied. Silver badge pursuit is tracked separately and may be addressed in a future issue.