fix(android): skip zero-duration auto-advance during UPnP playback

android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt

@@ -61,6 +61,7 @@ class PlayerController @Inject constructor(
     @ApplicationScope private val scope: CoroutineScope,
     private val radio: RadioController,
     private val playerFactory: PlayerFactory,
+    private val activeUpnpHolder: com.fabledsword.minstrel.player.output.ActiveUpnpHolder,
 ) {
 
     /**
@@ -321,6 +322,11 @@ class PlayerController @Inject constructor(
      * and advance past the dead track. Otherwise no-op.
      */
     private fun handleZeroDurationIfNeeded(controller: MediaController, idx: Int) {
+        // Skip during UPnP playback. ExoPlayer is intentionally paused and never
+        // buffers tracks, so duration is permanently 0 / TIME_UNSET -- without
+        // this guard we rapid-advance through the entire local queue (and spam
+        // /api/playback-errors) every time the user activates a UPnP route.
+        if (activeUpnpHolder.active.value != null) return
         val current = queueRefs.getOrNull(idx) ?: return
         val duration = controller.duration
         val isZeroDuration = duration <= 0L || duration == androidx.media3.common.C.TIME_UNSET