M0: toolchain, monorepo scaffold, gateway plugin skeleton, CMP app

- gateway-plugin/: android platform plugin (plugin.yaml + adapter.py
  register(ctx) + no-op AndroidAdapter) + stub modules for M1-M5
- app/: Compose Multiplatform project (shared KMP + androidApp +
  desktopApp) with Gradle wrapper; builds :androidApp:assembleDebug
  and :desktopApp:compileKotlin
- scripts/guard_hermes_agent.sh + pre-commit hook: fail if hermes-agent/
  is staged (read-only reference, never committed)
- .gitignore excludes hermes-agent/; docs/ reference library

app/androidApp/build.gradle.kts

@@ -0,0 +1,42 @@
+plugins {
+    id("com.android.application")
+    kotlin("android")
+    id("org.jetbrains.kotlin.plugin.compose")
+}
+
+android {
+    namespace = "dev.iris.app"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "dev.iris.app"
+        minSdk = 29
+        targetSdk = 34
+        versionCode = 1
+        versionName = "0.1.0"
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+}
+
+dependencies {
+    implementation(project(":shared"))
+    implementation(platform("androidx.compose:compose-bom:2024.09.02"))
+    implementation("androidx.compose.material3:material3")
+    implementation("androidx.compose.ui:ui")
+    implementation("androidx.activity:activity-compose:1.9.2")
+    implementation("androidx.core:core-splashscreen:1.0.1")
+}