Apply make fix-repo sweep + bf16 ESMFold2 usage example
`make fix-repo` adds the `add_dates` "contributed on …" stamp to the esmc/esmfold2
doc pages and ruff-reformats a few esmc files (line-length only, no logic change).
Also update the esmfold2.md usage example to the recommended `dtype=torch.bfloat16`.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
