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/home/SearchScreen.tsx

@@ -14,8 +14,7 @@ import {
   RefreshControl,
 } from 'react-native';
 import { SafeAreaView, useSafeAreaInsets } from 'react-native-safe-area-context';
-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, fontSizes, borderRadius } from '../../theme';
 import { Post, User } from '../../types';
@@ -24,12 +23,10 @@ import { postService, authService } from '../../services';
 import { PostCard, TabBar, SearchBar } from '../../components/business';
 import type { PostCardAction } from '../../components/business/PostCard';
 import { Avatar, EmptyState, Text, ResponsiveGrid, Loading } from '../../components/common';
-import { HomeStackParamList } from '../../navigation/types';
+import * as hrefs from '../../navigation/hrefs';
 import { useResponsive, useResponsiveSpacing, useResponsiveValue } from '../../hooks/useResponsive';
 import { useCursorPagination } from '../../hooks/useCursorPagination';
 
-type NavigationProp = NativeStackNavigationProp<HomeStackParamList, 'Search'>;
-
 const TABS = ['帖子', '用户'];
 const DEFAULT_PAGE_SIZE = 20;
 
@@ -37,12 +34,10 @@ type SearchType = 'posts' | 'users';
 
 interface SearchScreenProps {
   onBack?: () => void;
-  navigation?: NavigationProp;
 }
 
-export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation: propNavigation }) => {
-  // 如果传入了 navigation 则使用传入的，否则使用 hook 获取的
-  const navigation = propNavigation || useNavigation<NavigationProp>();
+export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
+  const router = useRouter();
   const insets = useSafeAreaInsets();
   const { searchHistory: history, addSearchHistory, clearSearchHistory } = useUserStore();
   
@@ -168,12 +163,12 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation:
 
   // 跳转到帖子详情
   const handlePostPress = (postId: string, scrollToComments: boolean = false) => {
-    navigation.navigate('PostDetail', { postId, scrollToComments });
+    router.push(hrefs.hrefPostDetail(postId, scrollToComments));
   };
 
   // 跳转到用户主页
   const handleUserPress = (userId: string) => {
-    navigation.navigate('UserProfile', { userId });
+    router.push(hrefs.hrefUserProfile(userId));
   };
 
   // 统一处理 PostCard 的操作（搜索页不支持删除）
@@ -515,7 +510,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation:
         </View>
         <TouchableOpacity
           style={[styles.cancelButton, { marginLeft: responsiveGap }]}
-          onPress={() => onBack ? onBack() : navigation.goBack()}
+          onPress={() => (onBack ? onBack() : router.back())}
           activeOpacity={0.85}
         >
           <Text