The public surface of the optimizer framework (EP-10).

optimize is the one stable entry point EP-12's CLI calls: it applies an Optimizer strategy to a starting program and returns a CompiledProgram. The shared search-state plumbing (selectBest, scoreOn, freezeProgram) lives in Shikumi.Optimize.Search and is re-exported here; the four strategies are re-exported from their own modules.

No global mutable state. Candidate programs are threaded as ordinary values through pure folds; the only effectful step is scoring a candidate (which runs it over the dataset via scoreOn). This is the "thread candidates explicitly" discipline the MasterPlan mandates.