Harden Android accessibility, localization and startup (#105)

Implement independent hardening and regression coverage. Keep #105 open for final feature and environment coverage after #106–#110; document the completion boundary and resume order.

android/performance/build.gradle.kts

@@ -0,0 +1,37 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
+plugins { alias(libs.plugins.android.test) }
+
+android {
+    namespace = "de.rfc1437.ironstorage.performance"
+    compileSdk = libs.versions.compileSdk.get().toInt()
+    targetProjectPath = ":app"
+    defaultConfig {
+        minSdk = libs.versions.minSdk.get().toInt()
+        targetSdk = libs.versions.compileSdk.get().toInt()
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes.create("benchmark") {
+        isDebuggable = true
+        signingConfig = signingConfigs.getByName("debug")
+        matchingFallbacks += "release"
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    experimentalProperties["android.experimental.self-instrumenting"] = true
+}
+
+kotlin {
+    jvmToolchain(25)
+    compilerOptions {
+        jvmTarget.set(JvmTarget.JVM_17)
+        allWarningsAsErrors.set(true)
+    }
+}
+
+dependencies {
+    implementation(libs.benchmark.macro)
+    implementation(libs.android.test.runner)
+}