Regular interval labels is non-functional

1. Have some audio
2. Go to Tools > Regular interval labels
3. Click Apply
4. Observe: The output "Nyquist returned the value: 2" is incorrect; it should produce 10 labels with 10-second intervals by default.

<img width="235" height="140" alt="Image" src="https://github.com/user-attachments/assets/e410fa77-a786-434c-bf40-3c2ef3348a13" />