## Summary

Describe the user-visible change and the pipeline stage it affects.

## Verification

- [ ] `python -m pytest -q`
- [ ] `python -m ruff check app.py utils.py cohere_stt.py modal_backend.py tests`
- [ ] Mock mode tested locally
- [ ] Modal path tested, or clearly marked as not tested
- [ ] No secrets, private images, or personal audio included
- [ ] Accessibility behavior preserved

## Model claims

- [ ] Model IDs and inference calls match current official model cards
- [ ] Parameter, language, and on-device claims are measured or explicitly framed as roadmap