Keep voice cleanup independent of caller cancellation and stop playback promptly

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

@@ -241,10 +241,10 @@ class AudioRecorderManager {
         while (true) {
             val previous = closing.get()
             if (previous != null && !previous.isDone) return previous
-            val next = CompletableFuture<Unit>()
+            val next = object : CompletableFuture<Unit>() { override fun cancel(mayInterruptIfRunning: Boolean): Boolean = false }
             if (closing.compareAndSet(previous, next)) { result = next; break }
         }
-        captureRunning = false; recordingThread?.interrupt()
+        captureRunning = false; recordingThread?.interrupt(); stopPlayback()
         try {
             Thread({
                 var retryMs = 250L

tools/chatgui-android/capture-tests/src/test/kotlin/com/utun/chat/data/AudioRecorderManagerTest.kt

@@ -185,6 +185,7 @@ class AudioRecorderManagerTest {
         val device = plan(); assertTrue(manager.startRecording("7")); device.failures = setOf("release")
         val closed = manager.requestClose()
         waitUntil { NativeLib.cancels.get() == 1 }
+        assertFalse(closed.cancel(true))
         assertFalse(closed.isDone); assertFalse(NativeLib.active)
         assertThrows(IllegalStateException::class.java) { AudioRecorderManager.requireReleasedForCore() }
         device.failures = emptySet(); closed.get(2, TimeUnit.SECONDS)