Fix macOS black video after re-parenting the shared player view

The player video surface is a single shared MPVOGLView that is re-parented
between the mini-bar container (main window) and the expanded-player sheet
(a separate sheet window). When presenting the sheet, the new container
attaches the shared view before the old mini-bar container tears down, so
the old container's viewWillMove(toSuperview: nil) was ripping the shared
view out of its new home via removeFromSuperview() — leaving it with no
window and a black surface. Symmetric, so it also blanked the mini-bar
preview after collapsing.

Only detach the shared view if it still belongs to the container
(superview === self). Also force a repaint on window reattach so a paused
frame redraws, and extend the onAppear resumeRendering to macOS.

Yattee/Services/Player/MPV/MPVOGLView.swift

@@ -170,6 +170,12 @@ final class MPVOGLView: NSView {
 
             // Update contents scale for new window
             videoLayer?.contentsScale = window.backingScaleFactor
+
+            // Reattaching (e.g. macOS player sheet dismissed via ESC then re-expanded)
+            // detaches this shared view without stopping playback. macOS drawing is
+            // pull-based, so force a redraw to repaint the current frame — otherwise
+            // the layer stays black until MPV emits a new frame (never, if paused).
+            resumeRendering()
         }
     }
 

Yattee/Views/Player/MPVRenderViewRepresentable.swift

@@ -184,10 +184,21 @@ private class MPVContainerNSView: NSView {
 
     override func viewWillMove(toSuperview newSuperview: NSView?) {
         super.viewWillMove(toSuperview: newSuperview)
-        // When being removed from superview, detach player view first
-        // This ensures proper cleanup order during window destruction
+        // When being removed from superview, detach the player view first for a clean
+        // teardown order during window destruction.
+        //
+        // The player view is a single SHARED instance (backend.playerView) that is
+        // re-parented between containers (mini bar ⇄ expanded sheet). When presenting
+        // the sheet, the new container attaches the shared view (AppKit auto-removes it
+        // from the old container) BEFORE this old container is torn down. So by the time
+        // we get here, `currentPlayerView` may already live in another container. Only
+        // remove it if it still actually belongs to us — otherwise we would rip the
+        // shared view out of its new home and blank the video (black screen on re-open,
+        // and a black mini-bar preview after collapse).
         if newSuperview == nil {
-            currentPlayerView?.removeFromSuperview()
+            if let playerView = currentPlayerView, playerView.superview === self {
+                playerView.removeFromSuperview()
+            }
             currentPlayerView = nil
             onDidMoveToWindow = nil
         }

Yattee/Views/Player/MPVVideoView.swift

@@ -143,11 +143,12 @@ struct MPVVideoView: View {
             applies: appliesAspectRatio
         ))
         .onAppear {
-            #if os(iOS)
+            #if os(iOS) || os(macOS)
             // Resume the MPV display link when the expanded video view appears.
             // MiniPlayerView pauses rendering when its video preview hides during expand;
             // PlayerService.playerSheetDidAppear is gated behind background playback, so it
-            // can't be relied on to resume.
+            // can't be relied on to resume. On macOS this also recovers the sheet re-open
+            // black screen when the shared render view reappears without a window re-parent.
             backend.resumeRendering()
             #endif
             // Start debug updates if overlay is already visible when view appears