feat: MeshCore SAR - Flutter BLE mesh radio companion app

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/build.gradle.kts

@@ -0,0 +1,75 @@
+import java.util.Properties
+import java.io.FileInputStream
+
+plugins {
+    id("com.android.application")
+    id("kotlin-android")
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle 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
+    ndkVersion = flutter.ndkVersion
+
+    // Enable BuildConfig generation
+    buildFeatures {
+        buildConfig = true
+    }
+
+    compileOptions {
+        isCoreLibraryDesugaringEnabled = true
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
+
+    defaultConfig {
+        applicationId = "com.meshcore.sar.meshcore_sar_app"
+        minSdk = flutter.minSdkVersion
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+
+        // Inject commit hash from environment variable (set by GitHub Actions)
+        // Falls back to "dev" for local development builds
+        val commitHash = System.getenv("COMMIT_HASH") ?: "dev"
+        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 {
+            signingConfig = signingConfigs.getByName("release")
+        }
+    }
+}
+
+flutter {
+    source = "../.."
+}
+
+dependencies {
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
+}