fix(uitests): stop logging out after every authenticated test

All 7 authenticated-flow XCTestCase classes logged out for real in
tearDown, forcing a real OTP round trip against the production backend
on the next authenticated test. Under CI's back-to-back suite run this
produced ~9 real logins to the same QA phone number in ~9 minutes -
the first few succeeded (~30-40s each) but every one after that failed
to complete within timeout, cascading into 'Login never completed'
across CartCheckoutFlowTests, HomeFiltersFlowTests,
OrderDetailsFlowTests, SavedCardsFlowTests, UserProfileFlowTests.

Removed the per-test logout so the QA account's Keychain-backed session
persists across the whole suite (ensureLoggedIn already no-ops when
already authenticated). Moved the 'must start logged out' guarantee to
the two classes that actually need it - HomeGuestFlowTests and
ProfileLoggedOutFlowTests now force logout themselves right after
app.launch() via a small launch helper, instead of relying on whichever
authenticated class happened to run last.

See decisions/2026-09-11-ui-test-shared-login-session.md.

PediFoodsUITests/ProfileLoggedOutFlowTests.swift

@@ -7,9 +7,19 @@ final class ProfileLoggedOutFlowTests: XCTestCase {
         continueAfterFailure = false
     }
 
-    func testLoggedOutProfileShowsLoginPrompt() throws {
+    /// Authenticated-flow tests no longer log out after themselves (see
+    /// decisions/2026-09-11-ui-test-shared-login-session.md), so
+    /// logged-out tests must force a clean state themselves right after
+    /// launch, rather than assume one.
+    private func launchLoggedOutApp() -> XCUIApplication {
         let app = XCUIApplication()
         app.launch()
+        app.logoutIfAuthenticated()
+        return app
+    }
+
+    func testLoggedOutProfileShowsLoginPrompt() throws {
+        let app = launchLoggedOutApp()
         XCTAssertTrue(app.reachLoggedOutProfile(), "Never reached the logged-out profile screen")
 
         XCTAssertTrue(app.staticTexts["Entre na sua conta"].exists)
@@ -22,8 +32,7 @@ final class ProfileLoggedOutFlowTests: XCTestCase {
     /// a working way back out (its `LCENavigationView` back button, which
     /// sets `root = .main`).
     func testAuthIntroScreenShowsChoicesAndCanGoBack() throws {
-        let app = XCUIApplication()
-        app.launch()
+        let app = launchLoggedOutApp()
         XCTAssertTrue(app.reachLoggedOutProfile())
 
         app.buttons["Entrar ou Cadastrar"].tap()
@@ -45,8 +54,7 @@ final class ProfileLoggedOutFlowTests: XCTestCase {
     /// app's standard `AppBackButtonIcon` via `LCENavigationView`, not the
     /// oversized iOS 26 system glass back button.
     func testPushedAuthScreensUseAppBackButton() throws {
-        let app = XCUIApplication()
-        app.launch()
+        let app = launchLoggedOutApp()
         XCTAssertTrue(app.reachLoggedOutProfile())
         app.buttons["Entrar ou Cadastrar"].tap()