Package-level declarations

SPI for Chromecast support (sender side). Apps construct a connector from the cast module (OGCastConnector) and pass it to OGPlayer.Builder.setCastConnector. When a cast session starts, the player hands playback off to the receiver at the current position and takes it back when the session ends — listeners and UI keep working.

Session availability callbacks, implemented by the SDK core.

Receiver connection state, as surfaced by OGPlayer.castState.