test(ios-runner): branch the busy-app assertion on what the command answered

The label check ran twice over the same response: it always expected `First actions: 1`, and the block
after it expected `First actions: 0` only when the answer was a deadline failure, so the second could
never pass and a correct refusal failed anyway. Now the assertion follows the answer — an accepted
alert must show the button press, a refused one must not — and the comment said "main thread busy"
where the fixture runs a repeating animation with the main thread free.

The test also joins the targeted list in `.github/workflows/ios.yml`, which is where the alert
regressions it guards are selected.

Author: thymikee

.github/workflows/ios.yml

@@ -187,6 +187,7 @@ jobs:
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testAlertCannotProveAnIdenticalReplacementAndDoesNotActivateIt \
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testAlertDeadlineBeforeActivationLeavesTheOriginalUntouched \
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testAlertHittableProbeCompletingAfterDeadlineLeavesTheOriginalUntouched \
+            -only-testing:AgentDeviceRunnerUITests/RunnerTests/testAlertActivationIgnoresAnAppThatNeverSettlesBeforeTheDeadline \
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testSystemModalProbeSliceSharesAndClampsToPlanDeadline \
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testDispatchRecoverySkipsBookkeepingWhileXCTestChannelOccupied \
             -only-testing:AgentDeviceRunnerUITests/RunnerTests/testBoundedSystemModalProbeTimeoutRecoversThenReleasesOnDrain \

apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+AlertObservationTests.swift

@@ -75,14 +75,17 @@ extension RunnerTests {
     let response = handleAlert(alert, action: "accept", deadline: deadline)
     let elapsed = Date().timeIntervalSince(startedAt)
 
-    // The fixture keeps its main thread busy until a button is answered, so this only comes back
-    // early because activation refused to wait for an app that has no intention of settling (#2546).
+    // The fixture keeps an animation in flight, which is what XCTest waits out before it synthesises
+    // an event, so this comes back early only because activation refused to wait for an app that has
+    // no intention of settling (#2546).
     XCTAssertLessThan(elapsed, 9, "activation waited \(elapsed)s for a busy app to idle")
     XCTAssertTrue(response.ok, String(describing: response.error))
-    XCTAssertEqual(app.staticTexts["agent-device-alert-actions"].label, "First actions: 1; replacement actions: 0")
-    if !response.ok, response.error?.code == "ALERT_DEADLINE_EXCEEDED" {
+    let recordedActions = app.staticTexts["agent-device-alert-actions"].label
+    if response.ok {
+      XCTAssertEqual(recordedActions, "First actions: 1; replacement actions: 0")
+    } else {
       XCTAssertEqual(
-        app.staticTexts["agent-device-alert-actions"].label,
+        recordedActions,
         "First actions: 0; replacement actions: 0",
         "a caller told about an expired deadline must not have a button activated behind it"
       )