A failed subtest fails its parent, so TestHarnessFailsTheTestWhenTheBundleAsksSomethingUnknown could never
pass the way it was written (try 2's finding). The player now reports through askFailer (Helper, Errorf);
every other test keeps passing its own *testing.T, which satisfies it already. That one test gives a
recorder instead, and asserts it holds exactly one message naming seat:mail-store.accounts, and that
mail-webclient.status's own answer shows the ask got an error back. Checked: no other integration test uses
the same deliberate-subtest-failure pattern (grepped t.Run).