Add skill management system with unlocker and save functionality

scripts/save_system.gd

@@ -0,0 +1,32 @@
+class_name SaveSystem
+extends Node
+
+@export var save_path: String = "user://savegame.save"
+@export var version: int = 1
+
+@onready var gm: GM = $"/root/GameManager"
+
+
+func save_game():
+	var save_data := {
+						 "player_state": gm.player_state,
+						 "version": version,
+					 }
+	var file      := FileAccess.open(save_path, FileAccess.WRITE)
+	file.store_var(save_data)
+	file.close()
+
+
+func load_game():
+	if not FileAccess.file_exists(save_path):
+		return
+	var file                  := FileAccess.open(save_path, FileAccess.READ)
+	var save_data: Dictionary =  file.get_var()
+	file.close()
+
+	if save_data.has("version") and save_data["version"] != version:
+		print("Save file version mismatch. Expected: ", version, ", Found: ", save_data["version"])
+		return
+
+	gm.player_state = save_data["player_state"]
+	gm.unlock_skills(gm.player_state["unlocked_skills"])