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/components/ChatScreen/ChatHeader.tsx

@@ -7,10 +7,10 @@ import React, { useMemo } from 'react';
 import { View, TouchableOpacity, StyleSheet } from 'react-native';
 import { SafeAreaView } from 'react-native-safe-area-context';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
-import { Avatar, Text } from '../../../../components/common';
+import { Avatar, Text, AppBackButton } from '../../../../components/common';
 import { colors, spacing } from '../../../../theme';
 import { chatScreenStyles as baseStyles } from './styles';
-import { useResponsive, useBreakpointGTE } from '../../../../hooks/useResponsive';
+import { useBreakpointGTE } from '../../../../hooks/useResponsive';
 import { ChatHeaderProps } from './types';
 
 export const ChatHeader: React.FC<ChatHeaderProps> = ({
@@ -26,7 +26,6 @@ export const ChatHeader: React.FC<ChatHeaderProps> = ({
   isWideScreen: propIsWideScreen,
 }) => {
   // 响应式布局
-  const { width } = useResponsive();
   // 使用 768px 作为大屏幕和小屏幕的分界线
   const isWideScreenHook = useBreakpointGTE('lg');
   // 优先使用 props 传入的 isWideScreen，否则使用 hook
@@ -74,12 +73,7 @@ export const ChatHeader: React.FC<ChatHeaderProps> = ({
       <View style={styles.header}>
         {/* 大屏幕（>= 768px）时隐藏返回按钮 */}
         {!isWideScreen ? (
-          <TouchableOpacity
-            style={styles.backButton}
-            onPress={onBack}
-          >
-            <MaterialCommunityIcons name="arrow-left" size={22} color={colors.primary.dark} />
-          </TouchableOpacity>
+          <AppBackButton style={styles.backButton} onPress={onBack} />
         ) : (
           <View style={styles.backButton} />
         )}
@@ -131,14 +125,14 @@ export const ChatHeader: React.FC<ChatHeaderProps> = ({
             style={styles.moreButton}
             onPress={onGroupInfoPress}
           >
-            <MaterialCommunityIcons name="dots-horizontal" size={22} color="#667085" />
+            <MaterialCommunityIcons name="dots-horizontal" size={22} color={colors.text.primary} />
           </TouchableOpacity>
         ) : (
           <TouchableOpacity
             style={styles.moreButton}
             onPress={onMorePress}
           >
-            <MaterialCommunityIcons name="dots-horizontal" size={22} color="#667085" />
+            <MaterialCommunityIcons name="dots-horizontal" size={22} color={colors.text.primary} />
           </TouchableOpacity>
         )}
       </View>