重构项目结构，删除未使用的组件和文件，添加主页和模态页实现

app/_layout.tsx

@@ -5,16 +5,10 @@ import {
 } from "@react-navigation/native";
 import { Stack } from "expo-router";
 import { StatusBar } from "expo-status-bar";
-import "react-native-reanimated";
-import "../global.css";
+import { useColorScheme } from "react-native";
 
-import { useColorScheme } from "@/hooks/use-color-scheme";
 import { AppBootstrapProvider } from "@/providers/app-bootstrap-provider";
 
-export const unstable_settings = {
-  anchor: "(tabs)",
-};
-
 export default function RootLayout() {
   const colorScheme = useColorScheme();
 
@@ -22,7 +16,7 @@ export default function RootLayout() {
     <AppBootstrapProvider>
       <ThemeProvider value={colorScheme === "dark" ? DarkTheme : DefaultTheme}>
         <Stack>
-          <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
+          <Stack.Screen name="index" options={{ headerShown: false }} />
           <Stack.Screen
             name="modal"
             options={{ presentation: "modal", title: "Modal" }}