Function ips_from_store 

pub fn ips_from_store(
    db_path: impl AsRef<Path>,
    tenant: &str,
    candidate_start_rung: u32,
) -> Result<IpsReport, StoreError>

Run IPS/SNIPS OPE from the trace store for a fixed candidate start-rung policy.

Traces without propensity are excluded from IPS and counted in n_with_propensity. Missing or unreadable store is treated as zero traces (same forgiving behaviour as ope_from_store).

Errors

Returns StoreError on a genuine database read error on an existing record.