Initial commit: Helios Tracker location responder app

Minimal Android app that receives LOCATE commands via ntfy push
notifications and replies with GPS coordinates + battery level.
Uses WorkManager, FusedLocationProvider, and OkHttp.

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

app/build.gradle.kts

@@ -0,0 +1,70 @@
+plugins {
+    alias(libs.plugins.android.application)
+    alias(libs.plugins.kotlin.compose)
+}
+
+android {
+    namespace = "com.example.helios_location_finder"
+    compileSdk {
+        version = release(36) {
+            minorApiLevel = 1
+        }
+    }
+
+    defaultConfig {
+        applicationId = "com.example.helios_location_finder"
+        minSdk = 24
+        targetSdk = 36
+        versionCode = 1
+        versionName = "1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    buildFeatures {
+        compose = true
+    }
+}
+
+dependencies {
+    implementation(libs.androidx.core.ktx)
+
+    // Compose
+    implementation(platform(libs.compose.bom))
+    implementation(libs.compose.ui)
+    implementation(libs.compose.ui.tooling.preview)
+    implementation(libs.compose.material3)
+    implementation(libs.activity.compose)
+    debugImplementation(libs.compose.ui.tooling)
+
+    // WorkManager
+    implementation(libs.work.runtime.ktx)
+
+    // Google Play Services Location
+    implementation(libs.play.services.location)
+
+    // OkHttp
+    implementation(libs.okhttp)
+
+    // Coroutines for Play Services .await()
+    implementation(libs.coroutines.play.services)
+
+    testImplementation(libs.junit)
+    androidTestImplementation(libs.androidx.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
+}