add expo app

apps/mobile/app/_layout.tsx

@@ -0,0 +1,62 @@
+import FontAwesome from '@expo/vector-icons/FontAwesome';
+import {
+  DarkTheme,
+  DefaultTheme,
+  ThemeProvider,
+} from '@react-navigation/native';
+import { useFonts } from 'expo-font';
+import { SplashScreen, Stack } from 'expo-router';
+import { useEffect } from 'react';
+import { useColorScheme } from 'react-native';
+
+export {
+  // Catch any errors thrown by the Layout component.
+  ErrorBoundary,
+} from 'expo-router';
+
+// eslint-disable-next-line camelcase
+export const unstable_settings = {
+  // Ensure that reloading on `/modal` keeps a back button present.
+  initialRouteName: '(tabs)',
+};
+
+// Prevent the splash screen from auto-hiding before asset loading is complete.
+SplashScreen.preventAutoHideAsync();
+
+export default function RootLayout() {
+  const [loaded, error] = useFonts({
+    // eslint-disable-next-line global-require
+    SpaceMono: require('../assets/fonts/SpaceMono-Regular.ttf'),
+    ...FontAwesome.font,
+  });
+
+  // Expo Router uses Error Boundaries to catch errors in the navigation tree.
+  useEffect(() => {
+    if (error) throw error;
+  }, [error]);
+
+  useEffect(() => {
+    if (loaded) {
+      SplashScreen.hideAsync();
+    }
+  }, [loaded]);
+
+  if (!loaded) {
+    return null;
+  }
+
+  return <RootLayoutNav />;
+}
+
+function RootLayoutNav() {
+  const colorScheme = useColorScheme();
+
+  return (
+    <ThemeProvider value={colorScheme === 'dark' ? DarkTheme : DefaultTheme}>
+      <Stack>
+        <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
+        <Stack.Screen name="modal" options={{ presentation: 'modal' }} />
+      </Stack>
+    </ThemeProvider>
+  );
+}