feat: Introduce a settings manager and UI for configuring video, audio, and control keybinds.

scripts/managers/settings_manager.gd

@@ -223,3 +223,11 @@ func get_control_text(action_name: String) -> String:
 	var code = get_control_keycode(action_name)
 	if code == -1: return "Unbound"
 	return OS.get_keycode_string(code)
+
+func is_key_used(keycode: int) -> String:
+	"""Check if a keycode is already assigned to any action."""
+	for action in settings.controls.keys():
+		if action == "use_controller": continue
+		if settings.controls[action] == keycode:
+			return action
+	return ""