- Every capability and code category must have one canonical owner and one canonical implementation. Do not scatter the same responsibility across modules or layers, and do not keep copied variants, forwarding compatibility wrappers, duplicate helpers, models, validators, SDK facades, or state machines. Search before adding code; if ownership is wrong, move/refactor it and delete the superseded implementation in the same change.
- Removing obsolete, invalid, or duplicate files must also remove every newly empty package, source-set, resource, test, documentation, or module directory in the same change. Do not preserve empty structure with `.gitkeep`; ignored Gradle/Kotlin/build outputs are not source directories and must not be treated as project structure.