Match the more familiar Unity-style object model instead of a struct-of-arrays ECS: GameObject hierarchy with type-indexed component queries, Transform inlined as the one performance-motivated exception. Data/behavior stay split the same way ECS required it, so hot-reload safety is unaffected. Also fixes an inconsistency in the previous reload sequence, which described migrating live component data on a contract change even though the Default ALC hosting contracts never unloads. Contract changes now explicitly require an editor restart instead. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N