cleanup: remove dead currentPlayPath, fix seekVoice _currentPlayingPath reset

- AudioRecorderManager: removed unused currentPlayPath (duplicate of ViewModel state)
- ChatViewModel: seekVoice now resets _currentPlayingPath on complete (prevents
  pause-on-already-ended after seek finishes)

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

@@ -185,7 +185,6 @@ class AudioRecorderManager {
     @Volatile var elapsedMs: Int = 0; private set
     var pausedElapsedMs: Int = 0; private set
     private var playThread: Thread? = null
-    private var currentPlayPath: String? = null
 
     fun playVoiceFile(filePath: String, onProgress: ((Float) -> Unit)? = null, onComplete: () -> Unit = {}) {
         playFromPosition(filePath, 0, onProgress, onComplete)
@@ -193,7 +192,7 @@ class AudioRecorderManager {
 
     fun playFromPosition(filePath: String, startMs: Int, onProgress: ((Float) -> Unit)? = null, onComplete: () -> Unit = {}) {
         stopPlayback()
-        isPaused = false; elapsedMs = startMs; playing = true; currentPlayPath = filePath
+        isPaused = false; elapsedMs = startMs; playing = true
 
         playThread = Thread {
             try {
@@ -246,7 +245,7 @@ class AudioRecorderManager {
             } catch (e: Exception) {
                 LogManager.addLog("ERROR", "AudioPlayer", "play error: ${e.message}")
             }
-            playing = false; isPaused = false; currentPlayPath = null
+            playing = false; isPaused = false
             onComplete()
         }.apply { start() }
     }

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -285,7 +285,7 @@ class ChatViewModel : ViewModel() {
     fun seekVoice(filePath: String, seekMs: Int, onDone: () -> Unit) {
         audioRecorder.stopPlayback()
         _currentPlayingPath = filePath
-        audioRecorder.playFromPosition(filePath, seekMs, onComplete = onDone)
+        audioRecorder.playFromPosition(filePath, seekMs, onComplete = { _currentPlayingPath = null; onDone() })
     }
 
     fun clearState() {