Function classify_raw 

pub fn classify_raw(
    vault_path: &Path,
    pp: &Passphrase,
    target_ref: &str,
    payload_json: &str,
    now: OffsetDateTime,
) -> Result<EventId, CliError>

FR2/§7.3: resolve an Unclassified row to a real imported payload (preserving the target EventId). The payload is supplied as JSON (EventPayload is Deserialize) — e.g. {"Acquire":{…}}.