Fix UI test failures: registration dismiss cascade, onboarding reset, test stability

- Fix registration flow dismiss cascade: chain fullScreenCover → sheet onDismiss
  so auth state is set only after all UIKit presentations are removed, preventing
  RootView from swapping LoginView→MainTabView behind a stale sheet
- Fix onboarding reset: set hasCompletedOnboarding directly instead of calling
  completeOnboarding() which has an auth guard that fails after DataManager.clear()
- Stabilize Suite1 registration tests, Suite6 task tests, Suite7 contractor tests
- Add clean-slate-per-suite via AuthenticatedUITestCase reset state
- Improve test account seeding and screen object reliability

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

iosApp/iosApp/Helpers/AccessibilityIdentifiers.swift

@@ -22,11 +22,13 @@ struct AccessibilityIdentifiers {
         static let registerConfirmPasswordField = "Register.ConfirmPasswordField"
         static let registerButton = "Register.RegisterButton"
         static let registerCancelButton = "Register.CancelButton"
+        static let registerErrorMessage = "Register.ErrorMessage"
 
         // Verification
         static let verificationCodeField = "Verification.CodeField"
         static let verifyButton = "Verification.VerifyButton"
         static let resendCodeButton = "Verification.ResendButton"
+        static let verificationLogoutButton = "Verification.LogoutButton"
     }
 
     // MARK: - Navigation

iosApp/iosApp/Helpers/UITestRuntime.swift

@@ -56,11 +56,13 @@ enum UITestRuntime {
         DataManager.shared.clear()
         OnboardingState.shared.reset()
         ThemeManager.shared.currentTheme = .bright
+        UserDefaults.standard.removeObject(forKey: "ui_test_user_verified")
 
-        // Re-apply onboarding completion after reset so tests that need
-        // both --reset-state and --complete-onboarding work correctly.
+        // Re-apply onboarding completion after reset. Set the flag directly
+        // because completeOnboarding() has an auth guard that fails here
+        // (DataManager was just cleared, so isAuthenticated is false).
         if shouldCompleteOnboarding {
-            OnboardingState.shared.completeOnboarding()
+            OnboardingState.shared.hasCompletedOnboarding = true
         }
     }