Function fetch_proof_local 

pub fn fetch_proof_local(
    tier0_data: &[u8],
    tier1_data: &[u8],
    tier2_data: &[u8],
    num_ranges: usize,
    nullifier: Fp,
    empty_hashes: &[Fp; 29],
    root29: Fp,
) -> Result<ImtProofData>

Perform a complete local PIR proof retrieval without HTTP.

This is used by pir-test local mode. It takes the tier data directly (as built by pir-export) and performs the YPIR operations in-process.