[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/Resources/Localizable.xcstrings

@@ -88,6 +88,9 @@
     },
     "Abrir Ajustes" : {
 
+    },
+    "Acesse sua conta" : {
+
     },
     "Acompanhamento em tempo real" : {
 
@@ -346,10 +349,6 @@
       "comment" : "A prompt asking users to share their opinion about the delivery.",
       "isCommentAutoGenerated" : true
     },
-    "Criar conta" : {
-      "comment" : "A link that navigates to the registration screen.",
-      "isCommentAutoGenerated" : true
-    },
     "Crie sua conta" : {
       "comment" : "A link that directs users to create an account.",
       "isCommentAutoGenerated" : true
@@ -748,9 +747,6 @@
     "Não recebeu o código?" : {
       "comment" : "A question displayed below the button to re-send the OTP.",
       "isCommentAutoGenerated" : true
-    },
-    "Não tem conta ainda?" : {
-
     },
     "Nenhum cartão cadastrado" : {