[Bug] extract_solution produces invalid source config for ThreePartition → FlowShopScheduling

[zazabap]

Summary

The ILP solver finds a valid target solution for FlowShopScheduling (Or(true)), but extract_solution maps back to a source config that evaluates to Or(false) for ThreePartition.

Reproduction

pred create --example ThreePartition -o tp.json
pred reduce tp.json --to FlowShopScheduling -o bundle.json
pred solve bundle.json

Target evaluates to Or(true), extracted source config evaluates to Or(false). Likely the same Lehmer-code decoding issue as #1000 and #1001.

Origin

Reduction implemented in PR #972.

Discovery Method

Same systematic CLI round-trip test as #1002. See #1005 for the CI integration proposal.

[zazabap]

Fix should include: Add assert_bf_vs_ilp (from src/rules/test_helpers.rs) to this reduction's closed-loop test. The helper already exists and is used by 56 other tests — this reduction just wasn't wired up to it. The current test only verifies extraction with brute-force witnesses, which happen to work. ILP finds structurally different valid witnesses that break extraction.

[zazabap]

Superseded by #1006. Root cause is unsound reduce_to() constructions, not extract_solution bugs.