Function verify_step_fact_transcript 

pub fn verify_step_fact_transcript(
    jsonl_path: &Path,
) -> Result<TranscriptVerified, VerifyError>

Verify a JSONL transcript file produced by JsonlFileSink.

Reads the file line by line, recomputes every leaf and chain value, and checks each against the checkpoints recorded on the line.

Errors

Returns VerifyError for any I/O failure, malformed line, or commitment mismatch.