RUN 4 (1540c0287) survived 9 epochs with stable grad_norm=0.44.
That commit INCLUDED reward normalization (÷pos_frac). The revert
in 09fb80baa removed it, and the resulting H100 run collapsed at
epoch 7 (grad_norm=0.000).
The reward normalization is part of the stable configuration.
experience_kernels.cu restored to exact RUN 4 state.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>