fix(apple-runner): accept the iOS 27 floating-bar back control outside the classic header band

apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Navigation.swift

@@ -3,6 +3,8 @@ import XCTest
 
 extension RunnerTests {
   static let navigationBackKeywords = ["back", "close", "cancel"]
+  static let systemBackButtonIdentifier = "BackButton"
+  static let floatingBarBackControlMaxYFraction: CGFloat = 0.4
   static let navigationFallbackVerificationDelay: TimeInterval = 0.25
 
   /// What one in-app `back` attempt concluded. `.unverified` carries the typed capture failure the
@@ -88,7 +90,11 @@ extension RunnerTests {
     let candidates = app.buttons.matching(Self.navigationBackPredicate()).allElementsBoundByIndex.compactMap {
       element -> (XCUIElement, Int)? in
       guard element.exists, element.isHittable else { return nil }
-      guard Self.isTopNavigationControlFrame(element.frame, in: frame) else { return nil }
+      guard Self.isTopNavigationBackCandidateFrame(
+        element.frame,
+        in: frame,
+        identifier: element.identifier
+      ) else { return nil }
       guard let rank = Self.navigationBackControlRank(
         label: element.label,
         identifier: element.identifier
@@ -132,6 +138,24 @@ extension RunnerTests {
     return candidate.midY >= window.minY && candidate.midY <= maxY
   }
 
+  /// UIKit names the system back control `BackButton`. That identity is the evidence that lets it sit
+  /// below the classic header band, where the iOS 27 floating toolbar places it (#3333); keyword-only
+  /// matches stay inside the band so content controls that merely say "back" are not tapped.
+  static func isTopNavigationBackCandidateFrame(
+    _ candidate: CGRect,
+    in window: CGRect,
+    identifier: String
+  ) -> Bool {
+    if isTopNavigationControlFrame(candidate, in: window) { return true }
+    guard identifier == systemBackButtonIdentifier,
+      SnapshotGeometry.isPositiveFinite(candidate), SnapshotGeometry.isPositiveFinite(window)
+    else {
+      return false
+    }
+    let maxY = window.minY + window.height * floatingBarBackControlMaxYFraction
+    return candidate.midY >= window.minY && candidate.midY <= maxY
+  }
+
   static func topLeadingNavigationFallbackPoint(in frame: CGRect) -> CGPoint? {
     guard SnapshotGeometry.isPositiveFinite(frame) else {
       return nil

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

@@ -51,6 +51,63 @@ extension RunnerTests {
     XCTAssertFalse(Self.isTopNavigationControlFrame(.infinite, in: window))
   }
 
+  func testTopNavigationBackCandidateAcceptsIOS27FloatingBarSystemBackButton() {
+    let window = CGRect(x: 0, y: 0, width: 466, height: 678)
+    let floatingBarBack = CGRect(x: 399, y: 175, width: 38, height: 38)
+
+    XCTAssertFalse(Self.isTopNavigationControlFrame(floatingBarBack, in: window))
+    XCTAssertTrue(
+      Self.isTopNavigationBackCandidateFrame(floatingBarBack, in: window, identifier: "BackButton")
+    )
+  }
+
+  func testTopNavigationBackCandidateRejectsKeywordOnlyMatchBelowHeaderBand() {
+    let window = CGRect(x: 0, y: 0, width: 466, height: 678)
+    let floatingBarBack = CGRect(x: 399, y: 175, width: 38, height: 38)
+
+    XCTAssertFalse(
+      Self.isTopNavigationBackCandidateFrame(floatingBarBack, in: window, identifier: "back-link")
+    )
+    XCTAssertFalse(
+      Self.isTopNavigationBackCandidateFrame(floatingBarBack, in: window, identifier: "")
+    )
+  }
+
+  func testTopNavigationBackCandidateBoundsSystemBackButtonToUpperWindow() {
+    // 40% of 932 is 372.8; the classic band ends at 180, so only the floating-bar bound decides.
+    let window = CGRect(x: 0, y: 0, width: 430, height: 932)
+
+    XCTAssertTrue(
+      Self.isTopNavigationBackCandidateFrame(
+        CGRect(x: 20, y: 348, width: 44, height: 44),
+        in: window,
+        identifier: "BackButton"
+      )
+    )
+    XCTAssertFalse(
+      Self.isTopNavigationBackCandidateFrame(
+        CGRect(x: 20, y: 356, width: 44, height: 44),
+        in: window,
+        identifier: "BackButton"
+      )
+    )
+    XCTAssertFalse(
+      Self.isTopNavigationBackCandidateFrame(.infinite, in: window, identifier: "BackButton")
+    )
+  }
+
+  func testTopNavigationBackCandidateKeepsClassicHeaderBandForKeywordMatches() {
+    let window = CGRect(x: 0, y: 0, width: 430, height: 932)
+
+    XCTAssertTrue(
+      Self.isTopNavigationBackCandidateFrame(
+        CGRect(x: 340, y: 84, width: 72, height: 44),
+        in: window,
+        identifier: "back-link"
+      )
+    )
+  }
+
   func testNavigationVisualVerificationSeparatesNoChangeFromNoSample() {
     XCTAssertEqual(
       Self.navigationVisualObservation(before: Data([1, 2, 3]), after: Data([1, 2, 4])),