Function replay_oracle 

pub fn replay_oracle(messages: &[Message], h: usize) -> OracleReport

Compute an OracleReport over messages with horizon h.

Given the demand signal (lexical file references plus tool-call id matches) the report records, for every turn t, the set of prior turns needed to satisfy demand from [t, t+h]. Pareto harnesses compare that set to what a [DerivePolicy] actually kept.