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/modal.tsx

@@ -1,29 +1,5 @@
-import { Link } from 'expo-router';
-import { StyleSheet } from 'react-native';
+import { ModalScreen } from "@/features/system/screens/modal-screen";
 
-import { ThemedText } from '@/components/themed-text';
-import { ThemedView } from '@/components/themed-view';
-
-export default function ModalScreen() {
-  return (
-    <ThemedView style={styles.container}>
-      <ThemedText type="title">This is a modal</ThemedText>
-      <Link href="/" dismissTo style={styles.link}>
-        <ThemedText type="link">Go to home screen</ThemedText>
-      </Link>
-    </ThemedView>
-  );
+export default function ModalRoute() {
+  return <ModalScreen />;
 }
-
-const styles = StyleSheet.create({
-  container: {
-    flex: 1,
-    alignItems: 'center',
-    justifyContent: 'center',
-    padding: 20,
-  },
-  link: {
-    marginTop: 15,
-    paddingVertical: 15,
-  },
-});