Fix stale queue after closing macOS player window with Cmd+W

Closing the separate player window via Cmd+W (or the traffic-light
button) stopped the player but left the queue populated, so the next
video tap showed the Play Now/Play Next/Add to Queue prompt. Clear the
queue in windowShouldClose to match the close button behavior.

Yattee/Views/Player/ExpandedPlayerWindowManager.swift

@@ -475,6 +475,10 @@ extension ExpandedPlayerWindowManager: NSWindowDelegate {
             // Clear reference first so hide() becomes a no-op
             playerWindow = nil
 
+            // Clear queue so closing the window fully ends the session,
+            // matching the close button behavior
+            appEnvironment?.queueManager.clearQueue()
+
             // Stop player BEFORE cleaning up window to avoid crash
             // The player must be stopped while views still exist to ensure
             // proper cleanup of render resources