feat: Implement core player movement with advanced pushing mechanics, define game modes, and introduce various new managers and UI components.

scripts/managers/player_input_manager.gd

@@ -1,5 +1,7 @@
 extends Node
 
+
+
 var player: Node3D
 var movement_manager: Node
 var race_manager: Node
@@ -98,6 +100,10 @@ func handle_unhandled_input(event):
 		var mode = LobbyManager.get_game_mode()
 		var is_sng = mode == GameMode.Mode.STOP_N_GO
 		
+		# Safety check for SettingsManager
+		if not SettingsManager:
+			return
+
 		# Get dynamic keybinds
 		var key_p1 = SettingsManager.get_control_keycode("powerup_1")
 		var key_p2 = SettingsManager.get_control_keycode("powerup_2")