feat(sdk-android): scaffold Android library module

AGP 8.11.0, Kotlin 2.1.21, minSdk 24, compileSdk 35, JDK 17
bytecode, no Compose dep. Uatu object exposes start/extract as
stubs; real implementation in tasks #6–8.

sdk/android/src/main/AndroidManifest.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" />

sdk/android/src/main/kotlin/dev/uatu/sdk/Uatu.kt

@@ -0,0 +1,18 @@
+package dev.uatu.sdk
+
+import android.app.Application
+
+object Uatu {
+    fun start(application: Application, configuration: Configuration = Configuration()) {
+        // stub — real implementation in tasks #6–8
+    }
+
+    fun extract(name: String, function: () -> Any?) {
+        // stub — registry lands in task #8
+    }
+}
+
+data class Configuration(
+    val socketName: String = "uatu-agent",
+    val pauseTimeoutMillis: Long = 5_000L,
+)