Upgrade to Android Gradle Plugin 9.0.0

- Update AGP 8.13.2 → 9.0.0, Gradle 8.14.3 → 9.1.0
- Migrate kotlin-android/parcelize to full plugin names
- Add buildConfig = true (AGP 9.0 defaults false)
- Migrate deprecated srcDirs() to directories API
- Update gradle-play-publisher 3.12.1 → 3.13.0
- Add android.newDsl=false workaround for play-publisher

gradle/wrapper/gradle-wrapper.properties

@@ -1,7 +1,7 @@
 #Mon Jul 07 14:05:29 CST 2025
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME