chore: bump to v2.0.0

- Upgrade typescript 4 → 5
- Upgrade @types/node 14 → 22
- Upgrade @vercel/ncc 0.25 → 0.38
- Update tsconfig for modern module resolution (bundler)
- Migrate REST API calls from client.issues to client.rest.issues
  (required by @actions/github v9)
- Target ES2022 for ErrorOptions support

Author: michalvankodev