feat: Add Makefile, Fastlane configuration, and update Android build settings for release management

android/app/build.gradle.kts

@@ -1,3 +1,6 @@
+import java.util.Properties
+import java.io.FileInputStream
+
 plugins {
     id("com.android.application")
     id("kotlin-android")
@@ -5,6 +8,13 @@ plugins {
     id("dev.flutter.flutter-gradle-plugin")
 }
 
+// Load keystore properties from key.properties file
+val keystorePropertiesFile = rootProject.file("key.properties")
+val keystoreProperties = Properties()
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
+}
+
 android {
     namespace = "com.meshcore.sar.meshcore_sar_app"
     compileSdk = flutter.compileSdkVersion
@@ -16,22 +26,17 @@ android {
     }
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_11
-        targetCompatibility = JavaVersion.VERSION_11
-        // Required by some dependencies (e.g., flutter_local_notifications)
-        // to support Java 8+ APIs on older Android devices.
         isCoreLibraryDesugaringEnabled = true
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_11.toString()
+        jvmTarget = JavaVersion.VERSION_17.toString()
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId = "com.meshcore.sar.meshcore_sar_app"
-        // You can update the following values to match your application needs.
-        // For more information, see: https://flutter.dev/to/review-gradle-config.
         minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode
@@ -43,11 +48,20 @@ android {
         buildConfigField("String", "COMMIT_HASH", "\"$commitHash\"")
     }
 
+    signingConfigs {
+        create("release") {
+            if (keystorePropertiesFile.exists()) {
+                keyAlias = keystoreProperties["keyAlias"] as String
+                keyPassword = keystoreProperties["keyPassword"] as String
+                storeFile = file(keystoreProperties["storeFile"] as String)
+                storePassword = keystoreProperties["storePassword"] as String
+            }
+        }
+    }
+
     buildTypes {
         release {
-            // TODO: Add your own signing config for the release build.
-            // Signing with the debug keys for now, so `flutter run --release` works.
-            signingConfig = signingConfigs.getByName("debug")
+            signingConfig = signingConfigs.getByName("release")
         }
     }
 }
@@ -57,6 +71,5 @@ flutter {
 }
 
 dependencies {
-    // Core library desugaring support library
     coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
 }