Local polish through rgmin

Hopping relaxations use anneal_core::methods::warm_lbfgs::WarmLbfgs, which is a handle around rgmin::Lbfgs. The two-loop recursion, the 7.20 scale, and the strong Wolfe search live in rgmin. This crate keeps the forget / watch / budget surface the chain needs.

The production choice is L-BFGS with strong Wolfe (Liu and Nocedal 1989; Nocedal and Wright 7.4 and algorithms 3.5–3.6). SciPy L-BFGS-B is the bound-constrained reference this handle was measured against. See the rgmin SOTA page in that crate’s docs/orgmode/reference/sota.org.