Block native teardown until viewer and shared mixer cleanup is confirmed

tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt

@@ -74,6 +74,7 @@ object NativeLib {
             RadioCallController.reset()
             StreamController.reset(); CallController.reset(); ChatApplication.instance.avatars.stop(); ChatApplication.instance.memberFiles.cancel()
             CallService.requireReleased() // Не останавливать native при неподтверждённой очистке его media-владельца.
+            StreamPlayerEngine.stopForCore()
             check(!CallController.blocksMedia()) {
                 LogManager.addLog("ERROR", "Call", "Core teardown blocked: call media preparation still running")
                 "Call media preparation still running"

tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamAudioMixer.kt

@@ -49,6 +49,14 @@ internal object StreamAudioMixer {
         LogManager.addLog("INFO", "stream", "shared audio output released for call")
     }
 
+    /** Проверка core teardown без join: живой worker удерживает Android output для retry. */
+    fun requireReleased() = synchronized(lock) {
+        check(inputs.isEmpty() && worker?.isAlive != true) {
+            LogManager.addLog("ERROR", "stream", "core teardown blocked by mixer inputs=${inputs.size} worker=${worker?.state}")
+            "Stream mixer cleanup pending"
+        }
+    }
+
     private fun run() {
         var audio: StreamAudioOutput? = null
         var generated = 0L

tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt

@@ -24,6 +24,19 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
         private val mutableViewing = MutableStateFlow(false)
         val viewing: StateFlow<Boolean> = mutableViewing
 
+        /** Main: запросить stop всех viewers; незавершённый cleanup запрещает native stop и допускает повтор. */
+        fun stopForCore() {
+            check(Looper.myLooper() == Looper.getMainLooper()) { "Viewer core teardown requires main" }
+            players.toList().forEach { it.stop() }
+            players.removeAll { player -> synchronized(player.releaseLock) { player.released } && player.worker?.isAlive != true }
+            mutableViewing.value = players.isNotEmpty()
+            check(players.isEmpty()) {
+                LogManager.addLog("ERROR", "stream", "core teardown blocked by viewers count=${players.size}; cleanup retained")
+                "Stream viewers cleanup pending"
+            }
+            StreamAudioMixer.requireReleased()
+        }
+
         /** Закрыть просмотр и дождаться освобождения AudioTrack/decoder вне main thread. */
         suspend fun stopForCall() {
             val stopped = players.toList()