pub const ATTESTATION_MAGIC: u32 = _; // 1_413_566_034u32Expand description
Marker for the optional attestation tail: "RNAT" little-endian.
Read as a u32 after the re-record count. A movie with no attestation simply
ends there, so the marker is what distinguishes “no attestation recorded” from
“attestation present” — absence is a fact, not a parse failure.