To audit what each UI test actually exercises, every step now snapshots the
live window to <TestFixtureName>/<TestName>_<NN>_<ShortDescription>.png: a
booted frame (emitted automatically by TestHarness.BootAsync), one after each
state-changing action, and one before each assertion. Flip ILSPY_TESTS_VISIBLE=1
to render the filmstrip; it lands under %TEMP%/ilspy-test-captures (overridable
via ILSPY_TEST_CAPTURES).
The step number and fixture/test name are derived automatically so inserting a
breakpoint never renumbers the rest. The identity is recorded up front from the
real ITest in an ITestAction hook rather than read live: NUnit's
TestContext.CurrentContext does not flow onto async continuations, so a capture
after an await would otherwise collide under the ad-hoc context. And when
rendering is off the whole call is a true no-op -- not even a dispatcher pump --
so instrumenting a test can never perturb the navigation/tab timing it asserts
on. Full headless suite stays green.