Phase 5: Translate Auth Pages - login and signup

- Create auth.json translation files for es, en, ca
- Translate login page: title, subtitle, form labels, buttons, footer
- Translate signup page: invite code step and account creation step
- Translate signup/[code] redirect page
- Update IntlProvider to load auth namespace
- Update test expectations to match Spanish translations (default language)
- All frontend and e2e tests passing

frontend/locales/ca/auth.json

@@ -0,0 +1,44 @@
+{
+  "login": {
+    "title": "Benvingut de nou",
+    "subtitle": "Inicia sessió al teu compte",
+    "email": "Correu electrònic",
+    "password": "Contrasenya",
+    "emailPlaceholder": "tu@exemple.com",
+    "passwordPlaceholder": "••••••••",
+    "signIn": "Iniciar sessió",
+    "signingIn": "Iniciant sessió...",
+    "noAccount": "No tens un compte?",
+    "signUp": "Registra't",
+    "loginFailed": "Error en iniciar sessió"
+  },
+  "signup": {
+    "title": "Uneix-te amb Invitació",
+    "subtitle": "Introdueix el teu codi d'invitació per començar",
+    "inviteCode": "Codi d'Invitació",
+    "inviteCodePlaceholder": "paraula-paraula-00",
+    "inviteHint": "Demana aquest codi al teu convidant",
+    "checking": "Comprovant...",
+    "continue": "Continuar",
+    "checkingInviteCode": "Comprovant codi d'invitació...",
+    "createAccount": "Crear compte",
+    "createAccountTitle": "Crear compte",
+    "createAccountSubtitle": "Utilitzant invitació:",
+    "email": "Correu electrònic",
+    "emailPlaceholder": "tu@exemple.com",
+    "password": "Contrasenya",
+    "passwordPlaceholder": "••••••••",
+    "confirmPassword": "Confirmar Contrasenya",
+    "confirmPasswordPlaceholder": "••••••••",
+    "creatingAccount": "Creant compte...",
+    "alreadyHaveAccount": "Ja tens un compte?",
+    "signIn": "Iniciar sessió",
+    "useDifferentCode": "Utilitzar un codi d'invitació diferent",
+    "redirecting": "Redirigint...",
+    "passwordsDoNotMatch": "Les contrasenyes no coincideixen",
+    "passwordTooShort": "La contrasenya ha de tenir almenys 6 caràcters",
+    "invalidInviteCode": "Codi d'invitació invàlid",
+    "failedToVerify": "Error en verificar codi d'invitació",
+    "registrationFailed": "Error en registrar-se"
+  }
+}

frontend/locales/en/auth.json

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+{
+  "login": {
+    "title": "Welcome back",
+    "subtitle": "Sign in to your account",
+    "email": "Email",
+    "password": "Password",
+    "emailPlaceholder": "you@example.com",
+    "passwordPlaceholder": "••••••••",
+    "signIn": "Sign in",
+    "signingIn": "Signing in...",
+    "noAccount": "Don't have an account?",
+    "signUp": "Sign up",
+    "loginFailed": "Login failed"
+  },
+  "signup": {
+    "title": "Join with Invite",
+    "subtitle": "Enter your invite code to get started",
+    "inviteCode": "Invite Code",
+    "inviteCodePlaceholder": "word-word-00",
+    "inviteHint": "Ask your inviter for this code",
+    "checking": "Checking...",
+    "continue": "Continue",
+    "checkingInviteCode": "Checking invite code...",
+    "createAccount": "Create account",
+    "createAccountTitle": "Create account",
+    "createAccountSubtitle": "Using invite:",
+    "email": "Email",
+    "emailPlaceholder": "you@example.com",
+    "password": "Password",
+    "passwordPlaceholder": "••••••••",
+    "confirmPassword": "Confirm Password",
+    "confirmPasswordPlaceholder": "••••••••",
+    "creatingAccount": "Creating account...",
+    "alreadyHaveAccount": "Already have an account?",
+    "signIn": "Sign in",
+    "useDifferentCode": "Use a different invite code",
+    "redirecting": "Redirecting...",
+    "passwordsDoNotMatch": "Passwords do not match",
+    "passwordTooShort": "Password must be at least 6 characters",
+    "invalidInviteCode": "Invalid invite code",
+    "failedToVerify": "Failed to verify invite code",
+    "registrationFailed": "Registration failed"
+  }
+}

frontend/locales/es/auth.json

@@ -0,0 +1,44 @@
+{
+  "login": {
+    "title": "Bienvenido de nuevo",
+    "subtitle": "Inicia sesión en tu cuenta",
+    "email": "Correo electrónico",
+    "password": "Contraseña",
+    "emailPlaceholder": "tu@ejemplo.com",
+    "passwordPlaceholder": "••••••••",
+    "signIn": "Iniciar sesión",
+    "signingIn": "Iniciando sesión...",
+    "noAccount": "¿No tienes una cuenta?",
+    "signUp": "Regístrate",
+    "loginFailed": "Error al iniciar sesión"
+  },
+  "signup": {
+    "title": "Únete con Invitación",
+    "subtitle": "Ingresa tu código de invitación para comenzar",
+    "inviteCode": "Código de Invitación",
+    "inviteCodePlaceholder": "palabra-palabra-00",
+    "inviteHint": "Pide este código a tu invitador",
+    "checking": "Verificando...",
+    "continue": "Continuar",
+    "checkingInviteCode": "Verificando código de invitación...",
+    "createAccount": "Crear cuenta",
+    "createAccountTitle": "Crear cuenta",
+    "createAccountSubtitle": "Usando invitación:",
+    "email": "Correo electrónico",
+    "emailPlaceholder": "tu@ejemplo.com",
+    "password": "Contraseña",
+    "passwordPlaceholder": "••••••••",
+    "confirmPassword": "Confirmar Contraseña",
+    "confirmPasswordPlaceholder": "••••••••",
+    "creatingAccount": "Creando cuenta...",
+    "alreadyHaveAccount": "¿Ya tienes una cuenta?",
+    "signIn": "Iniciar sesión",
+    "useDifferentCode": "Usar un código de invitación diferente",
+    "redirecting": "Redirigiendo...",
+    "passwordsDoNotMatch": "Las contraseñas no coinciden",
+    "passwordTooShort": "La contraseña debe tener al menos 6 caracteres",
+    "invalidInviteCode": "Código de invitación inválido",
+    "failedToVerify": "Error al verificar código de invitación",
+    "registrationFailed": "Error al registrarse"
+  }
+}