Constant OPTIONAL_U64_UNSET_WIRE 

const OPTIONAL_U64_UNSET_WIRE: u64 = u64::MAX; // 18_446_744_073_709_551_615u64

Wire encoding for clearing optional u64 compaction configs.

Note: meta currently treats both u64::MIN and u64::MAX as “unset” for historical reasons. SQL DEFAULT always sends u64::MAX to avoid overloading 0 at the SQL layer.