Function parse_lock_data_zone 

pub fn parse_lock_data_zone(payload: &[u8]) -> Result<(), PayloadError>

Parse the payload of CommandOpcode::LockDataZone.

Layout: magic (4). No CRC accompanies a data-zone lock because secret-bearing slots cannot be read back to compute one. The double-confirmation in the host CLI is the only safety beyond the magic word.

Errors

• PayloadError::WrongLen if the payload is not exactly 4 bytes.
• PayloadError::MagicMismatch if the first 4 bytes are not LOCK_DATA_MAGIC.