- Snapshot best-epoch weights during training and restore before
checkpoint/RVF export (prevents exporting overfit final-epoch params)
- Add CsiToPoseTransformer::zeros() for fast zero-init when weights
will be overwritten, avoiding wasteful Xavier init during gradient
estimation (~2*param_count transformer constructions per batch)
- Deduplicate synthetic data generation in main.rs training mode
Co-Authored-By: claude-flow <ruv@ruv.net>