Initial commit: Android Tether API app

Exposes phone connection status via HTTP API for tethered devices.

Features:
- Auto-start/stop server when tethering is enabled/disabled
- REST API with /status and /health endpoints
- Connection type, signal strength, carrier, battery info
- Foreground service with persistent notification

Stack: Kotlin 2.3, AGP 8.13, Gradle 8.13, compileSdk 36

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists