feat(game): improve mode state handling and active player UI

* Rename and consolidate ball state tracking across game modes
* Add ball finalization and win-condition hooks
* Track foul points by negating reaped ball points
* Update turn switching and ball processing flow
* Add active-player indicator to the camera controller UI
* Refresh active-player label when the turn changes

scenes/data/multiplayer_data.gd

@@ -22,6 +22,8 @@ func set_active_player_id(id: int) -> void:
 	push_warning("Server assigned active player: ", id)
 
 	current_turn_player_id = id
+	MessageBus.emit_local("update_active_lbl", null)
+
 
 func reset() -> void:
 	multiplayer_synchronizer                    = MultiplayerSynchronizer.new()