AGP 9.0 is Out, and Its a Disaster. Heres Full Migration Guide so you dont have to suffer

I migrated 150k lines of code to AGP 9.0 and wrote a comprehensive, step-by step guide to migrating large Kotlin Multiplatform projects from AGP 8 to AGP 9, covering all breaking changes including removed build types, BuildConfig issues, NDK restrictions, and the new DSL syntax.