build(mobile): require explicit validated Android release identity

apps/mobile/android/app/build.gradle

@@ -1,5 +1,22 @@
 apply plugin: 'com.android.application'
 
+// Release identity is explicit; ordinary developer builds retain the -dev label.
+def releaseVersion = providers.gradleProperty('aiturkReleaseVersion').orNull
+def releaseCode = providers.gradleProperty('aiturkReleaseVersionCode').orNull
+if ((releaseVersion == null) != (releaseCode == null)) {
+    throw new GradleException('Both aiturkReleaseVersion and aiturkReleaseVersionCode are required')
+}
+def selectedVersionCode = 5
+if (releaseVersion != null) {
+    if (!(releaseVersion ==~ /\d+\.\d+\.\d+(?:-beta\.\d+)?/)) {
+        throw new GradleException('Release version must be X.Y.Z or X.Y.Z-beta.N; -dev is not a release')
+    }
+    if (!(releaseCode ==~ /[1-9]\d{0,9}/) || releaseCode.toLong() <= 5 || releaseCode.toLong() > 2100000000L) {
+        throw new GradleException('Release version code must be greater than 5 and at most 2100000000')
+    }
+    selectedVersionCode = releaseCode.toInteger()
+}
+
 android {
     namespace = "online.turkservis.aiturk.mobile"
     compileSdk = rootProject.ext.compileSdkVersion
@@ -7,8 +24,8 @@ android {
         applicationId "online.turkservis.aiturk.mobile"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 5
-        versionName "0.1.4-dev"
+        versionCode selectedVersionCode
+        versionName releaseVersion ?: "0.1.4-dev"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         aaptOptions {
              // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.