优化画中画模式支持，添加播放器释放逻辑，修复相关引用管理

example/src/main/java/com/demo/SellyCloudSDK/FeatureHubActivity.kt

@@ -201,6 +201,7 @@ class FeatureHubActivity : AppCompatActivity() {
     }
 
     private fun handleAliveItemClick(item: AliveStreamItem) {
+        LivePlayActivity.closePipIfAny()
         val url = item.url?.trim().orEmpty()
         val intent = if (url.isNotEmpty()) {
             LivePlayActivity.createIntent(

example/src/main/java/com/demo/SellyCloudSDK/live/LivePlayActivity.kt

@@ -55,6 +55,7 @@ import kotlinx.coroutines.launch
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
+import java.lang.ref.WeakReference
 
 class LivePlayActivity : AppCompatActivity() {
 
@@ -80,6 +81,7 @@ class LivePlayActivity : AppCompatActivity() {
     private var firstAudioFrameCostMs: Long? = null
     private var isLatencyChasingActive: Boolean = false
     private var lastLatencyChasingSpeed: Float? = null
+    private var hasReleasedPlayer: Boolean = false
 
     private val logLines: ArrayDeque<String> = ArrayDeque()
     private val logTimeFormat = SimpleDateFormat("HH:mm:ss.SSS", Locale.getDefault())
@@ -209,9 +211,12 @@ class LivePlayActivity : AppCompatActivity() {
         logEvent("释放播放器")
         logDialog?.dismiss()
         if (this::playerClient.isInitialized) {
-            playerClient.release()
+            releasePlayerIfNeeded()
         }
         uiScope.cancel()
+        if (pipActivityRef?.get() === this) {
+            pipActivityRef = null
+        }
     }
 
     override fun onStop() {
@@ -228,6 +233,11 @@ class LivePlayActivity : AppCompatActivity() {
     override fun onPictureInPictureModeChanged(isInPictureInPictureMode: Boolean, newConfig: Configuration) {
         super.onPictureInPictureModeChanged(isInPictureInPictureMode, newConfig)
         updatePipUi(isInPictureInPictureMode)
+        if (isInPictureInPictureMode) {
+            pipActivityRef = WeakReference(this)
+        } else if (pipActivityRef?.get() === this) {
+            pipActivityRef = null
+        }
     }
 
     private fun togglePlay() {
@@ -258,6 +268,20 @@ class LivePlayActivity : AppCompatActivity() {
         pipController.enterPictureInPictureMode(renderView)
     }
 
+    private fun releasePlayerIfNeeded() {
+        if (hasReleasedPlayer) return
+        hasReleasedPlayer = true
+        playerClient.release()
+    }
+
+    private fun finishForNewPlayback() {
+        logEvent("外部请求: 结束画中画播放")
+        if (this::playerClient.isInitialized) {
+            releasePlayerIfNeeded()
+        }
+        finish()
+    }
+
     private fun startPlayback() {
         val env = envStore.read()
         args.playParams?.let { params ->
@@ -706,6 +730,8 @@ class LivePlayActivity : AppCompatActivity() {
     companion object {
         private const val TAG = "LivePlayActivity"
         private const val MAX_LOG_LINES = 200
+        @Volatile
+        private var pipActivityRef: WeakReference<LivePlayActivity>? = null
         const val EXTRA_PLAY_PROTOCOL = "play_protocol"
         const val EXTRA_STREAM_ID_OR_URL = "stream_id_or_url"
         const val EXTRA_PLAY_VHOST = "play_vhost"
@@ -741,6 +767,24 @@ class LivePlayActivity : AppCompatActivity() {
                 .putExtra(EXTRA_PLAY_STREAM_NAME, streamName)
                 .putExtra(EXTRA_AUTO_START, autoStart)
         }
+
+        fun closePipIfAny(): Boolean {
+            val activity = pipActivityRef?.get() ?: return false
+            if (activity.isDestroyed || activity.isFinishing) {
+                pipActivityRef = null
+                return false
+            }
+            if (!activity.isInPictureInPictureMode) {
+                pipActivityRef = null
+                return false
+            }
+            if (Looper.myLooper() == Looper.getMainLooper()) {
+                activity.finishForNewPlayback()
+            } else {
+                activity.runOnUiThread { activity.finishForNewPlayback() }
+            }
+            return true
+        }
     }
 
     private fun resolveChannelId(input: String): String {