1005 Tests, Zero AI: Building Offline-First Navigation with Flutter on Embedded Linux

SNGNav is an open-source Flutter navigation system for embedded Linux designed with an offline-first, deterministic, privacy-by-design approach—no AI or cloud dependency. Its architecture revolves around Five Guardians, independent subsystems each protecting against a different failure mode (GPS loss, network drop, etc.), ensuring graceful degradation rather than collapse. The project comprises 11 pub.dev packages with 1,005 tests and 91% line coverage, arguing that deterministic routing beats AI for regulatory compliance and that consent-by-default outperforms bolt-on privacy.