bb07bc8169
- Wrap _spectral_metrics + _save_spectrogram in try-except so a matplotlib or STFT error doesn't abort the checkpoint save (matches LoRA trainer) - Remove unused `import math` and `_pil_to_tensor` import - Drop dead `img` variable (_save_spectrogram returns None) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>