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/HoneyDueUITests/Framework/BaseUITestCase.swift

@@ -191,19 +191,35 @@ extension XCUIElement {
         // SecureTextFields may trigger iOS strong password suggestion dialog
         // which blocks the regular keyboard. Handle them with a dedicated path.
         if elementType == .secureTextField {
+            // Dismiss any open keyboard first — iOS 26 fails to transfer focus
+            // from a TextField to a SecureTextField if the keyboard is already up.
+            if app.keyboards.firstMatch.exists {
+                let navBar = app.navigationBars.firstMatch
+                if navBar.exists {
+                    navBar.tap()
+                }
+                _ = app.keyboards.firstMatch.waitForNonExistence(timeout: 2)
+            }
+
             tap()
             // Dismiss "Choose My Own Password" or "Not Now" if iOS suggests a strong password
             let chooseOwn = app.buttons["Choose My Own Password"]
-            if chooseOwn.waitForExistence(timeout: 1) {
+            if chooseOwn.waitForExistence(timeout: 0.5) {
                 chooseOwn.tap()
             } else {
                 let notNow = app.buttons["Not Now"]
                 if notNow.exists && notNow.isHittable { notNow.tap() }
             }
-            if app.keyboards.firstMatch.waitForExistence(timeout: 2) {
+            // Wait for keyboard after tapping SecureTextField
+            if !app.keyboards.firstMatch.waitForExistence(timeout: 5) {
+                // Retry tap — first tap may not have acquired focus
+                tap()
+                _ = app.keyboards.firstMatch.waitForExistence(timeout: 3)
+            }
+            if app.keyboards.firstMatch.exists {
                 typeText(text)
             } else {
-                app.typeText(text)
+                XCTFail("Keyboard did not appear after tapping SecureTextField: \(self)", file: file, line: line)
             }
             return
         }