Fix video player back button - use push navigation

Changed video player from .fullScreen to .push navigation:
- Removed NavigationViewCoordinator wrapper
- Video player now returns VideoPlayerCoordinator directly

This should allow ESC/back button to work during video playback.

MediaCoordinator kept at .fullScreen to prevent Home screen navigation bug.

Trade-offs:
✅ Video player ESC should now work
✅ Pressing back from empty channel goes to Media tab (not Home)
❌ Error dismissal still returns to Media tab (dismisses entire .fullScreen presentation)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Shared/Coordinators/ItemCoordinator.swift

@@ -40,7 +40,7 @@ final class ItemCoordinator: NavigationCoordinatable {
     var itemOverview = makeItemOverview
     @Route(.fullScreen)
     var mediaSourceInfo = makeMediaSourceInfo
-    @Route(.fullScreen)
+    @Route(.push)
     var videoPlayer = makeVideoPlayer
     #endif
 
@@ -90,8 +90,8 @@ final class ItemCoordinator: NavigationCoordinatable {
     #endif
 
     #if os(tvOS)
-    func makeVideoPlayer(manager: VideoPlayerManager) -> NavigationViewCoordinator<VideoPlayerCoordinator> {
-        NavigationViewCoordinator(VideoPlayerCoordinator(manager: manager))
+    func makeVideoPlayer(manager: VideoPlayerManager) -> VideoPlayerCoordinator {
+        VideoPlayerCoordinator(manager: manager)
     }
     #endif