fix(mpv): prevent UI freeze on player exit by tearing down mpv off main thread

mpv_terminate_destroy() blocks until mpv's threads (including the
vo_avfoundation output thread) are joined, and that teardown needs the
main run loop to complete. Calling it via queue.sync from MpvPlayerView
deinit (main thread) deadlocked/froze the UI on playback exit.

Remove the wakeup callback synchronously while self is still alive, then
run mpv_terminate_destroy on the serial queue via async so deinit returns
immediately and the main thread is never blocked. Also release the PiP
timebase/controller in deinit.

modules/mpv-player/ios/MPVLayerRenderer.swift

@@ -220,20 +220,27 @@ final class MPVLayerRenderer {
         statusObservation?.invalidate()
         statusObservation = nil
         
-        queue.sync { [weak self] in
-            guard let self, let handle = self.mpv else { return }
-            
-            mpv_set_wakeup_callback(handle, nil, nil)
-            mpv_terminate_destroy(handle)
+        if let handle = self.mpv {
             self.mpv = nil
+            // Remove the wakeup callback synchronously while `self` is still
+            // alive so it can never fire against a deallocated instance.
+            mpv_set_wakeup_callback(handle, nil, nil)
+            // Destroy mpv OFF the main thread. mpv_terminate_destroy() blocks
+            // until all mpv threads (including the vo_avfoundation output thread)
+            // are joined, and that teardown needs the main run loop to finish.
+            // Calling it via queue.sync from deinit (main thread) deadlocks/freezes
+            // the UI. queue.async only references `handle`, never `self`.
+            queue.async {
+                mpv_terminate_destroy(handle)
+            }
         }
         
-        DispatchQueue.main.async { [weak self] in
-            guard let self else { return }
+        let layer = self.displayLayer
+        DispatchQueue.main.async {
             if #available(iOS 18.0, *) {
-                self.displayLayer.sampleBufferRenderer.flush(removingDisplayedImage: true, completionHandler: nil)
+                layer.sampleBufferRenderer.flush(removingDisplayedImage: true, completionHandler: nil)
             } else {
-                self.displayLayer.flushAndRemoveImage()
+                layer.flushAndRemoveImage()
             }
         }
         

modules/mpv-player/ios/PiPController.swift

@@ -150,6 +150,16 @@ final class PiPController: NSObject {
             CMTimebaseSetRate(tb, rate: Float64(rate))
         }
     }
+    
+    deinit {
+        if let tb = timebase {
+            CMTimebaseSetRate(tb, rate: 0)
+        }
+        sampleBufferDisplayLayer?.controlTimebase = nil
+        timebase = nil
+        pipController?.delegate = nil
+        pipController = nil
+    }
 }
 
 // MARK: - AVPictureInPictureControllerDelegate