A hit returned the cached proof's stored grade, which is the closing
solver's own, beside a total of 0. So a goal whose first proof sealed
ModelBased (T0's modelled waste in its total) came back from the cache
sealed HwShunt 0 uJ: a measured zero for a span nothing metered, graded
above the proof it serves.
A hit's zero is the lookup's nominal cost, neither read nor modelled, so
it is Estimator. The stored CachedProof.provenance keeps its meaning, the
grade of the stored figure (the closing solver's own) and nothing else, so
cache files written before load and round-trip unchanged; the test loads
one such line, with HwShunt stored, and checks the hit is Estimator.
Published proof vectors regenerate byte-identical (no hit in the pack).
Co-Authored-By: Claude Opus 5.5 <[email protected]>