build: upgrade to Flutter 3.47.4 (AGP 9.1 / Gradle 9.3, iOS 15 + UIScene), refresh deps and CI

Flutter 3.24.5 -> 3.47.4 with the matching toolchain changes:

- pubspec: Dart ^3.11, Firebase core 4 / auth 6 / firestore 6 / storage 13,
  drop unused image_cropper, logging, change_app_package_name,
  pdf_widget_wrapper; pin path_provider_android <2.3 (needs NDK/CMake, not
  feasible on the ARM64 Gitea runner)
- Dart: CardTheme -> CardThemeData, replace deprecated withOpacity,
  Matrix4.scale, DropdownButtonFormField.value
- iOS: deployment target 15.0, UIScene lifecycle (AppDelegate/Info.plist),
  untrack stale Podfile.lock, add LaunchImage asset set
- Android: Gradle 9.3.1, AGP 9.1.0, Kotlin 2.4.0, google-services 4.5.0,
  layout.buildDirectory instead of removed Project.buildDir, remove manifest
  package attribute and duplicate MainActivity, kotlin.incremental=false
- CI: pin FLUTTER_VERSION in both workflows; iOS on macos-26 with SwiftPM
  disabled (CocoaPods only); Gitea job keeps cirruslabs 3.44.0 as base image
  (images discontinued) and switches the bundled Flutter SDK by git tag

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

android/app/build.gradle

@@ -1,60 +1,34 @@
 plugins {
     id "com.android.application"
-    id "kotlin-android"
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    // (With android.builtInKotlin=false the Flutter plugin applies kotlin-android itself.)
     id "dev.flutter.flutter-gradle-plugin"
     id "com.google.gms.google-services"
 }
 
-def localProperties = new Properties()
-def localPropertiesFile = rootProject.file('local.properties')
-if (localPropertiesFile.exists()) {
-    localPropertiesFile.withReader('UTF-8') { reader ->
-        localProperties.load(reader)
-    }
-}
-
-def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
-if (flutterVersionCode == null) {
-    flutterVersionCode = '1'
-}
-
-def flutterVersionName = localProperties.getProperty('flutter.versionName')
-if (flutterVersionName == null) {
-    flutterVersionName = '1.0'
-}
-
 android {
     namespace "com.oggauergemeindetrommler.app"
-    compileSdkVersion flutter.compileSdkVersion
-    ndkVersion "26.1.10909125"
+    compileSdk flutter.compileSdkVersion
+    ndkVersion flutter.ndkVersion
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_17
         targetCompatibility JavaVersion.VERSION_17
     }
 
-    kotlinOptions {
-        jvmTarget = '17'
-    }
-
     buildFeatures {
         buildConfig = true
     }
 
-    sourceSets {
-        main.java.srcDirs += 'src/main/kotlin'
-    }
-
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.oggauergemeindetrommler.app"
-        // You can update the following values to match your application needs.
-        // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
-        minSdkVersion 23
-        targetSdkVersion flutter.targetSdkVersion
-        versionCode flutterVersionCode.toInteger()
-        versionName flutterVersionName
-        multiDexEnabled true
+        // Flutter 3.47 defaults to 24; 23 (Android 6.0) is still supported and
+        // is also the minimum required by the current Firebase Android SDKs.
+        minSdkVersion flutter.minSdkVersion
+        targetSdk flutter.targetSdkVersion
+        // Read from pubspec.yaml (via local.properties); defaults to 1 / "1.0".
+        versionCode flutter.versionCode
+        versionName flutter.versionName
     }
 
     buildTypes {
@@ -66,8 +40,12 @@ android {
     }
 }
 
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
+    }
+}
+
 flutter {
     source '../..'
 }
-
-dependencies {}

android/app/src/main/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.oggauergemeindetrommler.app">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <application
         android:label="Oggauer Gemeindetrommler"
         android:name="${applicationName}"

android/app/src/main/kotlin/com/oggauergemeindetrommler/oggauer_gemeindetrommler/MainActivity.kt

@@ -1,6 +0,0 @@
-package com.oggauergemeindetrommler.oggauer_gemeindetrommler
-
-import io.flutter.embedding.android.FlutterActivity
-
-class MainActivity: FlutterActivity() {
-}

android/build.gradle

@@ -1,4 +1,3 @@
-
 allprojects {
     repositories {
         google()
@@ -6,28 +5,18 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+// Keep all Gradle outputs under <repo>/build so the Flutter CLI finds the APKs.
+// (Project.buildDir was removed in Gradle 9 -> use layout.buildDirectory.)
+def newBuildDir = rootProject.layout.buildDirectory.dir("../../build").get()
+rootProject.layout.buildDirectory.value(newBuildDir)
+
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
-}
-subprojects {
-    
-    // Inject namespace into plugins that don't have it (required for AGP 8+)
-    afterEvaluate { project ->
-        if (project.hasProperty('android')) {
-            project.android {
-                if (namespace == null) {
-                    namespace project.group
-                }
-            }
-        }
-    }
+    project.layout.buildDirectory.value(newBuildDir.dir(project.name))
 }
 subprojects {
     project.evaluationDependsOn(':app')
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }
-

android/gradle.properties

@@ -1,3 +1,11 @@
-org.gradle.jvmargs=-Xmx1536M -Djdk.lang.Process.launchMechanism=vfork
+# vfork keeps process spawning cheap under QEMU user-mode emulation (ARM64 CI runner).
+org.gradle.jvmargs=-Xmx4G -XX:MaxMetaspaceSize=1G -XX:+HeapDumpOnOutOfMemoryError -Djdk.lang.Process.launchMechanism=vfork
 android.useAndroidX=true
-android.enableJetifier=true
+# Stay on the legacy AGP DSL / external Kotlin plugin until all Flutter plugins
+# support the AGP 9 built-in Kotlin (same as the Flutter 3.47 project template).
+android.newDsl=false
+android.builtInKotlin=false
+# Kotlin incremental compilation stores project-relative paths and breaks on Windows
+# when the pub cache (C:) and the project live on different drives
+# ("this and base files have different roots"). CI builds are clean anyway.
+kotlin.incremental=false

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-8.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-all.zip

android/settings.gradle

@@ -20,11 +20,14 @@ pluginManagement {
     }
 }
 
+// Versions follow the Flutter 3.47 project template (see
+// packages/flutter_tools/lib/src/android/gradle_utils.dart in the Flutter SDK).
+// Flutter refuses to build with AGP < 8.11.1, Kotlin < 2.2.20 or Gradle < 8.14.
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "8.5.2" apply false
-    id "org.jetbrains.kotlin.android" version "1.9.22" apply false
-    id "com.google.gms.google-services" version "4.4.1" apply false
+    id "com.android.application" version "9.1.0" apply false
+    id "org.jetbrains.kotlin.android" version "2.4.0" apply false
+    id "com.google.gms.google-services" version "4.5.0" apply false
 }
 
 include ":app"