- Add Hermes webhook settings form in /admin/settings (URL + HMAC secret)
- Add /admin/request/<id>/send-to-hermes action
- POST request data to Hermes with V2 HMAC signature and callback URL
- Hermes can POST the generated MusicGPT prompt back to /api/prompt/<id>
- Add test button, update README workflow, bump version to 0.9.0