workmanager 0.5.2 references the removed PluginRegistrantCallback and other V1 Flutter embedding APIs, causing a Kotlin compilation failure when building the release AAB with AGP 8.11.1 / Kotlin 2.2.20. 0.9.x uses only V2 embedding. API migration: ExistingWorkPolicy → ExistingPeriodicWorkPolicy for registerPeriodicTask. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>