water-sys/App.tsx

import React from 'react';
import { NavigationContainer } from '@react-navigation/native';
import { createNativeStackNavigator } from '@react-navigation/native-stack';
import { CountrySelect } from './app/screens/CountrySelect';
import { MainApp } from './app/screens/MainApp';
import { LoginScreen } from './app/screens/LoginScreen';
import './app/i18n';

export type RootStackParamList = {
  CountrySelect: undefined;
  MainApp: undefined;
  Login: undefined;
};

const Stack = createNativeStackNavigator<RootStackParamList>();

export default function App() {
  return (
    <NavigationContainer>
      <Stack.Navigator
        initialRouteName="CountrySelect"
        screenOptions={{
          headerShown: false,
        }}
      >
        <Stack.Screen name="CountrySelect" component={CountrySelect} />
        <Stack.Screen 
          name="Login" 
          component={LoginScreen}
          options={{
            presentation: 'modal',
            animation: 'slide_from_bottom',
            gestureEnabled: true,
            gestureDirection: 'vertical'
          }}
        />
        <Stack.Screen name="MainApp" component={MainApp} />
      </Stack.Navigator>
    </NavigationContainer>
  );
}