Fix cascading crash and remaining UI test failures

- Revert key-by-key UserDefaults iteration that removed system keys
  causing kAXErrorServerNotFound crashes; restore removePersistentDomain
  with explicit subscription key clearing
- Add .accessibilityElement(children: .contain) to UpgradeBannerView
  so subscribe button is discoverable by XCUITest
- Fix AllDayViewStylesTests to use coordinate-based tapping instead of
  button.isHittable/button.tap() for iOS 26 Liquid Glass compatibility
- Improve OnboardingTests with multiple swipe retries and label-based
  fallback for skip button

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/UITestMode.swift

@@ -92,12 +92,15 @@ enum UITestMode {
     /// Reset all user defaults and persisted state for a clean test run
     @MainActor
     private static func resetAppState() {
-        // Clear group user defaults by iterating all keys.
-        // removePersistentDomain(forName:) is unreliable on app group suites.
         let defaults = GroupUserDefaults.groupDefaults
-        for key in defaults.dictionaryRepresentation().keys {
-            defaults.removeObject(forKey: key)
-        }
+        // Clear group user defaults using the suite domain name
+        defaults.removePersistentDomain(forName: Constants.currentGroupShareId)
+
+        // Explicitly clear subscription cache keys that may survive removePersistentDomain
+        // on app group suites (known reliability issue).
+        defaults.removeObject(forKey: UserDefaultsStore.Keys.cachedSubscriptionExpiration.rawValue)
+        defaults.removeObject(forKey: UserDefaultsStore.Keys.hasActiveSubscription.rawValue)
+        defaults.removeObject(forKey: UserDefaultsStore.Keys.firstLaunchDate.rawValue)
 
         // Reset key defaults explicitly (true = fresh install state where onboarding is needed)
         defaults.set(true, forKey: UserDefaultsStore.Keys.needsOnboarding.rawValue)

Shared/Views/SettingsView/SettingsTabView.swift

@@ -148,6 +148,7 @@ struct UpgradeBannerView: View {
             RoundedRectangle(cornerRadius: 14)
                 .fill(colorScheme == .dark ? Color(.systemGray6) : Color(.systemGray6).opacity(0.5))
         )
+        .accessibilityElement(children: .contain)
         .accessibilityIdentifier(AccessibilityID.Settings.upgradeBanner)
     }
 }