Changelog
- Add warden_report_t struct mirror in Warden.cs with StructLayout Pack=1 to match the native #pragma pack(1) (the trailing challenge_nonce u64 lands on an 8-unaligned offset; default packing would pad and break the round-trip)
- Add warden_decode_report / warden_encrypt_report externs returning WardenStatus
- Add report constants: ReportMagic, ReportVersion, ReportNonceSize, ReportTagSize, and sizeof-derived ReportBodySize / ReportWireSize
- Add WardenConfirmedFlag / WardenEnvironmentFlag [Flags] enums to interpret confirmed_flags (cheat-class) vs environment_flags (false-positive-prone)