Add access token check to auth

auth-new/errors.go

@@ -26,6 +26,10 @@ var (
 	ErrInvalidPasskeyRegistrationData = errors.New(
 		"stored passkey registration data was formatted badly",
 	)
+	// The given token has expired
+	ErrTokenExpired = errors.New("token expired")
+	// The given token doesn't exist
+	ErrTokenNotFound = errors.New("token not found")
 )
 
 // Helper error type to combine two errors into one