pub fn compress_payload(payload: &[u8]) -> Result<CompressedPayload>Expand description
Compress a payload for sealing, choosing the codec per the SPEC §1.1 raw threshold.
Uses zstd (id 1) only when the payload is at least MIN_COMPRESS_BYTES AND zstd actually shrinks
it; otherwise falls back to raw (id 0) so small or incompressible payloads never pay a header/
expansion penalty.
§Errors
MessageError::PayloadTooLarge if the payload does not fit the u32 length field;
MessageError::Codec on a zstd encoder failure.