The Z3 "Smallest Weight Update" Solver

To bridge Lean 4 formalisms with actual neural network weights (PyTorch/JAX), we implement the Z3 "Smallest Weight Update" Solver as a constrained optimization layer.

In our Newton's Cradle PBT, this solver ensures that when a "Lead" agent (Source) strikes a "Follower" (Target), the resulting weight shift is the minimal perturbation that satisfies the Lean-proven Social Welfare Contract.

(Code goes here)