docs: some more debug prints, for cleanup diag

app/src/main/cpp/PlaybackEngine.cpp

@@ -184,6 +184,8 @@ void PlaybackEngine::mapChannels(int *channel_map, int num_ch_in, int num_ch_out
 }
 
 void PlaybackEngine::musicFeedThread() {
+    LOGI("starting musicFeedThread()");
+
     // strecher num channels: same as output num channels
     // (this is because we play silence even without any input file, so we cannot set stretcher
     // channel count for the music file's channel count)
@@ -299,15 +301,19 @@ void PlaybackEngine::musicFeedThread() {
         stretcher.process(buf_ptr, num_decoded_samples, false);
     }
 
+    LOGI("musicFeedThread() exiting ...");
+
     free(buf);
     free(buf_ptr);
     free(cbuf);
     free(channel_map);
+
+    LOGI("musicFeedThread() exited.");
 }
 
 PlaybackEngine::~PlaybackEngine() {
-    closeRubberBand();
     LOGI("~PlaybackEngine()");
+    closeRubberBand();
     mPlayer->stopAudio();
     delete mPlayer;
     mPlayer = nullptr;

app/src/main/java/at/lockstep/app/LstForegroundService.java

@@ -15,6 +15,7 @@ import android.os.Build;
 import android.os.IBinder;
 import android.os.ParcelFileDescriptor;
 import android.os.PowerManager;
+import android.util.Log;
 import android.widget.Toast;
 
 import androidx.annotation.Nullable;
@@ -128,7 +129,7 @@ public class LstForegroundService extends Service implements SensorEventListener
             return;
         }
 
-        startForeground(NOTIFICATION_ID, buildNotification("Collecting sensor data"));
+        startForeground(NOTIFICATION_ID, buildNotification("Lockstep is reading your steps ..."));
 
         if (wakeLock != null && !wakeLock.isHeld()) {
             // TODO: provide a timeout reasonable for a run
@@ -174,6 +175,8 @@ public class LstForegroundService extends Service implements SensorEventListener
         // TODO: check threading to see if these run in separate threads - if so, deleting PlaybackEngine will leave a dangling pointer in StepDetector.
         // 2026-03-04 01:26:11.741 12507-12507 libc                    at.lockstep                          A  Fatal signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xb4000071d3a79000 in tid 12507 (at.lockstep), pid 12507 (at.lockstep)
 
+        Log.d("LstForegroundService", "onDestroy(), calling PlaybackEngine.delete()");
+
         if(stepDetector != null) {
             stepDetector.close();
             PlaybackEngine.delete();