Function build_checkpoint_consistency_proof 

pub fn build_checkpoint_consistency_proof(
    previous: &KernelCheckpoint,
    current: &KernelCheckpoint,
    chain_leaf_hashes: &[Hash],
) -> Result<CheckpointConsistencyProof, CheckpointError>

Build a Merkle consistency proof showing that current’s chain commitment is an append-only extension of previous’s.

chain_leaf_hashes must contain the chain leaf of every checkpoint from sequence 1 through current, in order (see checkpoint_chain_leaf_hash). Both checkpoints must carry a signed chain_root and both roots must match the supplied leaves; the proof fails to build rather than committing to unverified data.