Test that a sealed grant hides its words, not two letters

The check looked for "rt" in a random base64 ciphertext, which holds it
about one time in seventy, and failed mesh-catalog #141's repo check by
chance.

modules/claude-licence-manager/cmd/claude-licence-manager/store_test.go

@@ -110,7 +110,8 @@ func TestAGrantAtRestOpensOnlyWithItsKey(t *testing.T) {
 	a, _ := NewCrypt("one key")
 	b, _ := NewCrypt("another key")
 	sealed := a.Seal(`{"refreshToken":"rt"}`)
-	if strings.Contains(sealed, "rt") {
+	// The plaintext's own words, not two letters a random ciphertext holds one time in about seventy.
+	if strings.Contains(sealed, "refreshToken") {
 		t.Fatal("stored in the clear")
 	}
 	if got, err := a.Open(sealed); err != nil || got != `{"refreshToken":"rt"}` {