feat: implement production release configuration and signing for Play Store

ANDROID_KOTLIN_PLAN.md

@@ -141,6 +141,11 @@ Kurz: Ziel ist eine native Android-App mit Kotlin + Jetpack Compose, die die Web
  [ ] 22. Analytics: Firebase / Matomo Integration (je nach Datenschutz)
  [x] 23. Crash-Reporting: Sentry / Crashlytics integrieren
  [ ] 24. Build/Release: App signing, Release-Notes, Play-Store-Metadaten vorbereiten
+     - [x] Technische Release-Basis vorbereitet: `ANDROID_VERSION_CODE` und `ANDROID_VERSION_NAME` als Gradle-Properties eingeführt (`android-app/gradle.properties`) und im App-Gradle verdrahtet.
+     - [x] Production-Release-Flavor auf Produktiv-Backend parametrisierbar gemacht (`PRODUCTION_API_BASE_URL`, Default `https://harheimertc.de/`).
+     - [x] Release-Signing per sicheren Gradle-Properties vorbereitet (`RELEASE_STORE_FILE`, `RELEASE_STORE_PASSWORD`, `RELEASE_KEY_ALIAS`, `RELEASE_KEY_PASSWORD`) statt Hardcoding.
+     - [x] `:app:assembleProductionRelease` erfolgreich gebaut (Stand 2026-05-29).
+     - [ ] Offen: Finales Upload-Keystore + Credentials in CI/Build-Host hinterlegen, Play-Store-Release-Notes und Store-Metadaten pflegen.
  [ ] 25. Dokumentation: `README-android.md` mit Setup, Architektur und Release-Anleitung
 
 5) Kurzzeit-MVP (Priorität für erste Version)

android-app/app/build.gradle.kts

@@ -8,9 +8,31 @@ plugins {
 val localApiBaseUrl = providers.gradleProperty("LOCAL_API_BASE_URL")
     .orElse("https://harheimertc.tsschulz.de/")
     .get()
+val productionApiBaseUrl = providers.gradleProperty("PRODUCTION_API_BASE_URL")
+    .orElse("https://harheimertc.de/")
+    .get()
 val sentryDsn = providers.gradleProperty("SENTRY_DSN")
     .orElse("")
     .get()
+val androidVersionCode = providers.gradleProperty("ANDROID_VERSION_CODE")
+    .orElse("2")
+    .get()
+    .toInt()
+val androidVersionName = providers.gradleProperty("ANDROID_VERSION_NAME")
+    .orElse("1.0.0")
+    .get()
+val releaseMinifyEnabled = providers.gradleProperty("RELEASE_MINIFY_ENABLED")
+    .orElse("true")
+    .get()
+    .toBoolean()
+val releaseStoreFile = providers.gradleProperty("RELEASE_STORE_FILE").orNull
+val releaseStorePassword = providers.gradleProperty("RELEASE_STORE_PASSWORD").orNull
+val releaseKeyAlias = providers.gradleProperty("RELEASE_KEY_ALIAS").orNull
+val releaseKeyPassword = providers.gradleProperty("RELEASE_KEY_PASSWORD").orNull
+val hasReleaseSigning = !releaseStoreFile.isNullOrBlank() &&
+    !releaseStorePassword.isNullOrBlank() &&
+    !releaseKeyAlias.isNullOrBlank() &&
+    !releaseKeyPassword.isNullOrBlank()
 
 android {
     namespace = "de.harheimertc"
@@ -19,9 +41,38 @@ android {
     defaultConfig {
         applicationId = "de.harheimertc"
         minSdk = 24
-        targetSdk = 34
+        targetSdk = 35
-        versionCode = 1
+        versionCode = androidVersionCode
-        versionName = "0.1.0"
+        versionName = androidVersionName
+    }
+
+    signingConfigs {
+        create("release") {
+            if (hasReleaseSigning) {
+                storeFile = file(releaseStoreFile!!)
+                storePassword = releaseStorePassword
+                keyAlias = releaseKeyAlias
+                keyPassword = releaseKeyPassword
+            }
+        }
+    }
+
+    buildTypes {
+        getByName("release") {
+            isMinifyEnabled = releaseMinifyEnabled
+            isShrinkResources = false
+            ndk {
+                // Generate a native debug symbols archive for Play Console uploads.
+                debugSymbolLevel = "SYMBOL_TABLE"
+            }
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro",
+            )
+            if (hasReleaseSigning) {
+                signingConfig = signingConfigs.getByName("release")
+            }
+        }
     }
 
     flavorDimensions += "environment"
@@ -46,7 +97,7 @@ android {
         }
         create("production") {
             dimension = "environment"
-            buildConfigField("String", "API_BASE_URL", "\"https://harheimertc.tsschulz.de/\"")
+            buildConfigField("String", "API_BASE_URL", "\"$productionApiBaseUrl\"")
             buildConfigField("String", "SENTRY_DSN", "\"$sentryDsn\"")
             buildConfigField("String", "ENVIRONMENT_NAME", "\"\"")
             manifestPlaceholders["usesCleartextTraffic"] = "false"
@@ -72,6 +123,44 @@ android {
     }
 }
 
+val packageNativeDebugSymbolsForProductionRelease = tasks.register<Zip>("packageNativeDebugSymbolsForProductionRelease") {
+    group = "distribution"
+    description = "Packages production release native libraries into a Play Console debug symbols zip."
+    dependsOn(":app:mergeProductionReleaseNativeLibs")
+    from(layout.buildDirectory.dir("intermediates/merged_native_libs/productionRelease/mergeProductionReleaseNativeLibs/out/lib"))
+    destinationDirectory.set(layout.buildDirectory.dir("outputs/native-debug-symbols/productionRelease"))
+    archiveFileName.set("native-debug-symbols.zip")
+}
+
+val collectPlayStoreArtifacts = tasks.register("collectPlayStoreArtifacts") {
+    group = "distribution"
+    description = "Builds production release artifacts and collects AAB, mapping, and native symbols for Play Console upload."
+    dependsOn(":app:bundleProductionRelease")
+    dependsOn(packageNativeDebugSymbolsForProductionRelease)
+
+    doLast {
+        val outputDir = layout.buildDirectory.dir("outputs/playstore/productionRelease").get().asFile
+        outputDir.mkdirs()
+
+        val bundleFile = layout.buildDirectory.file("outputs/bundle/productionRelease/app-production-release.aab").get().asFile
+        if (bundleFile.exists()) {
+            bundleFile.copyTo(outputDir.resolve(bundleFile.name), overwrite = true)
+        }
+
+        val mappingFile = layout.buildDirectory.file("outputs/mapping/productionRelease/mapping.txt").get().asFile
+        if (mappingFile.exists()) {
+            mappingFile.copyTo(outputDir.resolve("mapping.txt"), overwrite = true)
+        }
+
+        val nativeSymbolsZip = layout.buildDirectory.file("outputs/native-debug-symbols/productionRelease/native-debug-symbols.zip").get().asFile
+        if (nativeSymbolsZip.exists()) {
+            nativeSymbolsZip.copyTo(outputDir.resolve("native-debug-symbols.zip"), overwrite = true)
+        }
+
+        println("Play Store artifacts prepared in: ${outputDir.absolutePath}")
+    }
+}
+
 kotlin {
     compilerOptions {
         jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)

android-app/app/proguard-rules.pro

@@ -0,0 +1,2 @@
+# Project-specific R8/ProGuard rules for release builds.
+# Keep this file intentionally minimal and add rules only when needed.

android-app/gradle.properties

@@ -3,3 +3,22 @@ org.gradle.jvmargs=-Xmx2048m -XX:MaxMetaspaceSize=512m -Dfile.encoding=UTF-8
 org.gradle.workers.max=2
 # Local API base URL for running the app from Android Studio / Gradle
 LOCAL_API_BASE_URL=https://harheimertc.tsschulz.de/
+
+# Production backend for Play Store build variant
+PRODUCTION_API_BASE_URL=https://harheimertc.de/
+
+# Android app versioning for Play Store uploads
+ANDROID_VERSION_CODE=3
+ANDROID_VERSION_NAME=1.0.0
+
+# Enable R8 for release by default so mapping.txt is generated for Play Console.
+RELEASE_MINIFY_ENABLED=true
+
+# Release signing (set in local, untracked gradle.properties or via CI secrets)
+# RELEASE_STORE_FILE=/absolute/path/to/keystore.jks
+# RELEASE_STORE_PASSWORD=***
+# RELEASE_KEY_ALIAS=***
+# RELEASE_KEY_PASSWORD=***
+
+# Build and collect Play Store upload artifacts:
+# ./gradlew :app:collectPlayStoreArtifacts