Constant ONIRO_ENVELOPE_SCHEMA_VERSION 

pub const ONIRO_ENVELOPE_SCHEMA_VERSION: u32 = 1;

The original version of oniro’s machine envelope this consumer understands.

Oniro’s schema documents that schema_version tracks INCOMPATIBLE change only, and that a consumer MUST refuse a version it does not know — so this is an equality check, not a floor. This public constant retains its version-1 value for existing users; the parser additionally accepts the explicitly supported schema-2 envelope below.