Function ope_from_store 

pub fn ope_from_store(
    db_path: impl AsRef<Path>,
    tenant: &str,
    policy: &CandidatePolicy,
) -> Result<OpeReport, StoreError>

Run OPE from the trace store.

Missing or unreadable store is treated as zero traces (returns a zero-trace report and exits 0), matching the forgiving behaviour of firstpass calibrate and firstpass trace.

Errors

Returns StoreError if a stored trace’s deferred verdicts cannot be read (a genuine database error on an existing record, not a missing store).