Release 0.3.1.

Included since 0.3.0

• rholrate schedule fix (maxdecs-ratcheted ceiling) in PyTorch/NumPy (Reset rholrate per iteration to match Fortran #194, issue rholrate decays permanently instead of resetting per iteration (Fortran parity) #193) and MLX (Fix MLX rholrate to ratchet at maxdecs (#195) #197, issue MLX backend: rholrate decays per-decrease (same bug as #193) #195).
• Native binary build: reproducible seed option in input.param + portable random_seed(SIZE=) (Wire reproducible seed into native build #196, from sccn/amica Refuse degenerate fits in the AMICA wrapper (#50) #54).
• AMICATorchNG diverges from Fortran on weak components at 2000 iters, despite Newton making the optimum sharply unique #145 investigation documented (init-basin sensitivity, not a dynamics bug); enhancement follow-up Improve NG init-robustness on under-determined components (best-of-N restarts) #198.

Version synced across pyproject.toml / CITATION.cff / .zenodo.json / uv.lock; changelog updated. Cutting the v0.3.1 release after merge triggers release-binaries.yml (rebuilds + uploads the seed-enabled native binaries) and the PyPI publish.