fix(android): pin AGP 8.9.1 + Gradle 8.11.1 (flutter_inappwebview proguard 호환)

flutter create 기본값 AGP 9.0.1이 getDefaultProguardFile('proguard-android.txt')
지원을 제거해 flutter_inappwebview 빌드 실패 → androidx.core 1.17.0 최소요구(8.9.1)와
겹치는 8.9.1로 고정. APK 빌드 통과 확인.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

android/gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-all.zip

android/settings.gradle.kts

@@ -19,8 +19,11 @@ pluginManagement {
 
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
-    id("com.android.application") version "9.0.1" apply false
-    id("org.jetbrains.kotlin.android") version "2.3.20" apply false
+    // AGP 9.x removed getDefaultProguardFile('proguard-android.txt') (used by
+    // flutter_inappwebview); AGP <8.9.1 is too old for androidx.core 1.17.0.
+    // → pin to 8.9.1 (the overlap) with Gradle 8.11.1.
+    id("com.android.application") version "8.9.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.1.0" apply false
 }
 
 include(":app")