feat(soter): wire supervisor into App startup

Start SoterProcessSupervisor from App.main() so the Layer-A forge
mounts on the on-demand soterserver process. prepareEnvironment() now
returns the system Context it previously discarded; main() hands it to
start() after keystore init and before Looper.loop(). start() runs on
its own HandlerThread and returns at once, so neither the blocking
keystore loop nor the message loop is affected.

The stub types ActivityThread.getSystemContext() as a bare ContextImpl,
so the Context cast warns CAST_NEVER_SUCCEEDS; the real ContextImpl does
extend Context, so it is runtime-safe and the warning is suppressed.

Checkpoint 10.W. compileDebugKotlin clean.

app/src/main/java/org/matrix/TEESimulator/App.kt

@@ -13,6 +13,7 @@ import org.matrix.TEESimulator.config.ConfigurationManager
 import org.matrix.TEESimulator.interception.keystore.AbstractKeystoreInterceptor
 import org.matrix.TEESimulator.interception.keystore.Keystore2Interceptor
 import org.matrix.TEESimulator.interception.keystore.KeystoreInterceptor
+import org.matrix.TEESimulator.interception.soter.SoterProcessSupervisor
 import org.matrix.TEESimulator.logging.SystemLogger
 import org.matrix.TEESimulator.pki.NativeCertGen
 import org.matrix.TEESimulator.util.AndroidDeviceUtils
@@ -39,7 +40,7 @@ object App {
         }
 
         try {
-            prepareEnvironment()
+            val systemContext = prepareEnvironment()
 
             // Spoof boot-state props before any hook attaches, so keystore2's
             // cached snapshot reflects the spoofed values.
@@ -62,6 +63,10 @@ object App {
 
             NativeCertGen.initialize("/data/adb/modules/tricky_store/libcertgen.so")
 
+            // Mount the SOTER forge on the on-demand soterserver process. The supervisor
+            // binds and (re)injects on its own thread, returning at once so it never blocks the loop.
+            SoterProcessSupervisor.start(systemContext)
+
             // This starts the message queue processing. It blocks here indefinitely
             // processing messages until Looper.myLooper().quit() is called.
             Looper.loop()
@@ -72,7 +77,7 @@ object App {
     }
 
     /** Initializes the necessary Android framework internals to satisfy KeyStore requirements. */
-    private fun prepareEnvironment() {
+    private fun prepareEnvironment(): Context {
         // 1. Prepare Main Looper
         if (Looper.getMainLooper() == null) {
             @Suppress("deprecation") Looper.prepareMainLooper()
@@ -81,8 +86,10 @@ object App {
         // 2. Initialize ActivityThread for the current process
         val activityThread = ActivityThread.systemMain()
 
-        // 3. Get the system context
+        // 3. Get the system context. The stub declares getSystemContext(): ContextImpl
-        val systemContext = activityThread.getSystemContext()
+        //    (a bare class), so cast to the Context it really is at runtime for the wiring.
+        @Suppress("CAST_NEVER_SUCCEEDS")
+        val systemContext = activityThread.getSystemContext() as Context
 
         // 4. Create a dummy Application object and attach the context
         val app = Application()
@@ -97,6 +104,8 @@ object App {
             ActivityThread::class.java.getDeclaredField("mInitialApplication")
         mInitialApplicationField.isAccessible = true
         mInitialApplicationField.set(activityThread, app)
+
+        return systemContext
     }
 
     /**