Android Kotlin Core

This is your foundation layer for writing idiomatic Kotlin in Android projects without the Java hangover. It handles the boring but critical stuff: tightening nullability at platform boundaries, replacing verbose helpers with focused extension functions, and using sealed types for UI state instead of stringly-typed bundles. The workflow is deliberate about keeping changes minimal and tied to actual Android surfaces, with explicit handoffs to testing or state management skills when scope creeps. The anti-patterns section is honest about real problems like sprinkling utilities everywhere or refactoring adjacent files just because you're nearby. If you're cleaning up a codebase that still looks like translated Java or you need to establish consistent Kotlin patterns across modules, this gives you guardrails and a clear done state.