Initial release.

• iOS video playback with a 100% native pipeline: AVPlayer + AVPlayerItem + AVPlayerLayer rendered through a platform view (CastVideoView), driven from Dart over platform channels (CastPlayerController).
• YouTube-style AirPlay via external playback: URL hand-off to the receiver, AVRoutePickerView cast button (CastButton), "Playing on TV" state exposed as CastPlayerValue.isExternalPlaybackActive + route name.
• Paused frame stays on the TV: pause never touches the audio session, the player item, or the player layer.
• Silent native keep-alive defeats the ~30s paused-session idle timeout of third-party AirPlay receivers (Samsung and friends) — the failure mode reported in plug-and-pay/flutter-native-video-player#54.
• Frame-accurate seeking, playback speed control that survives pause/resume, buffering/position/duration/error event stream, audio interruption and route-loss handling, background playback during casting.