chore: update dependencies and fix security vulnerabilities

- Fix 4 security vulnerabilities via npm audit fix
- Update @babel/helpers to 7.28.4 (fixes moderate severity RegExp issue)
- Update brace-expansion, nanoid, and semver (fixes DoS vulnerabilities)
- Remaining 2 moderate vulnerabilities in documentation (dev dependency only)

All 183 unit tests passing.

Author: charlypa