refactor(App, navigation): migrate to Expo Router and clean up navigation structure

- Updated App entry point to utilize Expo Router, simplifying the navigation setup.
- Removed legacy navigation components and services to streamline the codebase.
- Adjusted package.json to reflect the new entry point and updated dependencies for compatibility.
- Enhanced overall application structure by consolidating navigation logic and improving maintainability.

src/screens/message/JoinGroupScreen.tsx

@@ -10,8 +10,7 @@ import {
   FlatList,
   RefreshControl,
 } from 'react-native';
-import { useNavigation } from '@react-navigation/native';
-import { NativeStackNavigationProp } from '@react-navigation/native-stack';
+import { useRouter } from 'expo-router';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
 
 import { colors, spacing, borderRadius } from '../../theme';
@@ -19,15 +18,12 @@ import Avatar from '../../components/common/Avatar';
 import Text from '../../components/common/Text';
 import { groupService } from '../../services/groupService';
 import { groupManager } from '../../stores/groupManager';
-import { RootStackParamList } from '../../navigation/types';
 import { GroupResponse, JoinType } from '../../types/dto';
 import { useCursorPagination } from '../../hooks/useCursorPagination';
 import { EmptyState } from '../../components/common';
 
-type NavigationProp = NativeStackNavigationProp<RootStackParamList>;
-
 const JoinGroupScreen: React.FC = () => {
-  const navigation = useNavigation<NavigationProp>();
+  const router = useRouter();
   const [keyword, setKeyword] = useState('');
   const [searching, setSearching] = useState(false);
   const [joiningGroupId, setJoiningGroupId] = useState<string | null>(null);
@@ -92,7 +88,7 @@ const JoinGroupScreen: React.FC = () => {
       Alert.alert('成功', '操作已提交', [
         {
           text: '确定',
-          onPress: () => navigation.goBack(),
+          onPress: () => router.back(),
         },
       ]);
     } catch (error: any) {
@@ -106,13 +102,13 @@ const JoinGroupScreen: React.FC = () => {
     }
   };
 
-  const handleCopyGroupId = (groupId: string | number) => {
-    Clipboard.setString(String(groupId));
+  const handleCopyGroupId = (groupId: string) => {
+    Clipboard.setString(groupId);
     Alert.alert('已复制', '群号已复制到剪贴板');
   };
 
-  const formatGroupNo = (id: string | number) => {
-    const raw = String(id);
+  const formatGroupNo = (id: string) => {
+    const raw = id;
     if (raw.length <= 12) return raw;
     return `${raw.slice(0, 6)}...${raw.slice(-4)}`;
   };