substantial work on saving and loading and hub mechanic

scripts/scene_changer.gd

@@ -0,0 +1,30 @@
+extends Area3D
+
+@export var scene_path : String
+@export var scene_name : String
+@export var gamemode : gamemode 
+@export var scene_thumbnail : Texture2D
+
+var active = false
+
+# Called when the node enters the scene tree for the first time.
+func _ready() -> void:
+	pass # Replace with function body.
+
+
+# Called every frame. 'delta' is the elapsed time since the previous frame.
+func _process(delta: float) -> void:
+	pass
+
+
+func _on_body_entered(body: Node3D) -> void:
+	if active:
+		if get_tree().current_scene.gamemode.load_save == true:
+			SaveLoad.save_game_data(get_tree().current_scene.get_name())
+		SaveLoad.save_persistent_data()
+		SignalBus.emit_signal("player_exiting_tree")
+		get_tree().change_scene_to_file(scene_path)
+
+
+func _on_start_activation_timeout() -> void:
+	active = true