[auth-payment-login-lockout] Make auth intro a clean screen with a back button

App Review rejected the 2026-08 build: tapping checkout as a guest
switched root to .auth, which replaced the whole UI with LoginView as the
NavigationStack root - no nav bar, no back, no dismiss. User was trapped.

- LoginView: rebuilt as a static screen in LCENavigationView with a back
  button that sets root = .main, a 'Criar conta' and an 'Entrar' button,
  and 'Termos de Uso' / 'Politica de Privacidade' links. Added #Preview.
- Forced .preferredColorScheme(.light) and fixed DS colors (the app has
  no dark theme, so system dark mode was inverting the nav bar / title).
- Removed the entry-reveal animation machinery (heroVisible/textVisible/
  buttonVisible/token/prepare flags across LoginView, AuthFlowView,
  ContentView) - dead since guest browsing shipped and the root cause of
  the 2026-08-06 'content stuck hidden' bug.
- enterAuthFlow() is now just root = .auth.
- UITestSupport.ensureLoggedIn taps 'Entrar' (new label).
- ProfileLoggedOutFlowTests: new test covering the choices and the way
  back out of .auth.
- Localizable.xcstrings: catalog caught up to the new/removed strings.

PediFoods/Views/Auth/AuthFlowView.swift

@@ -11,21 +11,12 @@ struct AuthFlowView: View {
     @Binding var selectedTab: MainTab
     let tokenStore: TokenStore
     @Binding var appState: AppState
-    var shouldPrepareLoginEntry: Bool = false
-    var authEntryAnimationToken: Int = 0
 
     @State var path: [Route] = []
 
     var body: some View {
         NavigationStack(path: $path) {
-            LoginView(
-                root: $root,
-                selectedTab: $selectedTab,
-                tokenStore: tokenStore,
-                appState: $appState,
-                shouldPrepareEntryAnimation: shouldPrepareLoginEntry,
-                authEntryAnimationToken: authEntryAnimationToken
-            ) { route in
+            LoginView(root: $root) { route in
                 path.append(route)
             }
             .navigationDestination(for: Route.self) { route in