Add Android APK fleet nodes with Crucible UI integration and tests.

APK wrapper registers platform=android via AETHERFORGE_PLATFORM; fleet UI shows robot icons, Android Access Depth probes, and a shortened mining onion timeline.

android/agent-app/app/build.gradle.kts

@@ -0,0 +1,57 @@
+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+}
+
+android {
+    namespace = "com.aetherforge.agent"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.aetherforge.agent"
+        minSdk = 26
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0.0-phase1"
+
+        ndk {
+            abiFilters += listOf("arm64-v8a", "armeabi-v7a")
+        }
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+        }
+        debug {
+            applicationIdSuffix = ""
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    packaging {
+        jniLibs {
+            useLegacyPackaging = true
+        }
+    }
+
+    applicationVariants.all {
+        outputs.all {
+            val output = this as com.android.build.gradle.internal.api.BaseVariantOutputImpl
+            output.outputFileName = "aetherforge-agent.apk"
+        }
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.12.0")
+    implementation("androidx.appcompat:appcompat:1.6.1")
+}