updating to use clerk auth with new routing to signin page by default

app/(tabs)/_layout.tsx

@@ -21,7 +21,7 @@ export default function TabLayout() {
             }}
         >
             <Tabs.Screen
-                name='index'
+                name='home'
                 options={{
                     title: 'Home',
                     headerShown: false,
@@ -35,7 +35,6 @@ export default function TabLayout() {
                 options={{
                     title: 'Posts',
                     headerShown: false,
-                    tabBarItemStyle: { display: isAdmin ? 'flex' : 'none' },
                     tabBarIcon: ({ color, focused }) => (
                         <Ionicons name={focused ? 'rocket-sharp' : 'rocket-outline'} size={24} color={color} />
                     )