Add proxy routing and sing-box support

packages/flutter_tor/android/build.gradle

@@ -22,6 +22,16 @@ allprojects {
     }
 }
 
+def weblibreGoMobileAar = file("../../../native/go_mobile_runtime/build/weblibre-go.aar")
+def requireWebLibreGoMobileAar = {
+    if (!weblibreGoMobileAar.exists()) {
+        throw new GradleException(
+            "Missing combined gomobile runtime AAR: ${weblibreGoMobileAar}. " +
+                "Run native/go_mobile_runtime/scripts/build-android.sh from the repository root."
+        )
+    }
+}
+
 apply plugin: "com.android.library"
 apply plugin: "kotlin-android"
 
@@ -53,8 +63,9 @@ android {
         implementation("info.guardianproject:tor-android:0.4.9.6")
         implementation("info.guardianproject:jtorctl:0.4.5.7")
 
-        // Pluggable transports
-        implementation("com.netzarchitekten:IPtProxy:5.4.1")
+        // Pluggable transports are provided by the app-level combined gomobile AAR.
+        requireWebLibreGoMobileAar()
+        compileOnly(files(weblibreGoMobileAar))
 
         // Coroutines for async operations
         implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.10.2")