ci(license): add automated dependency license compliance audit (#717)

[ravendevhub]

Summary

Resolves #717 by establishing an automated dependency license auditor script (scripts/audit-licenses.py) and GitHub Actions CI workflow (.github/workflows/dependency-license-audit.yml) to continuously inspect direct and transitive licenses across Node.js and Rust environments against our approved open-source policy.

Changes

1. License Audit Script (scripts/audit-licenses.py):
   • Parses package.json, package-lock.json, and Cargo.toml manifests.
   • Evaluates packages against permissive open-source licenses (MIT, Apache-2.0, BSD, ISC, 0BSD, BlueOak-1.0.0, etc.).
   • Identifies non-standard or restrictive copyleft licenses for review.
2. CI Workflow (.github/workflows/dependency-license-audit.yml):
   • Executes automatically on pull requests touching dependency manifests.
3. Policy Documentation (docs/DEPENDENCY_LICENSE_POLICY.md):
   • Documents approved license list and local validation commands.

Acceptance Criteria

• Existing dependencies are evaluated.
• Dependency licenses can be inspected automatically.
• Unexpected licenses cause an actionable CI result.
• An approved license policy is documented.