fix(navigation): 修正双端（端口）切换的角色与入口问题

- 身份选项类型 hr→enterprise，与全局 AppRole 对齐（消除类型不一致）
- 两端 layout 将 setRole 由 useEffect 改为 useFocusEffect，
  根治「从企业端返回求职端」后 role 残留 enterprise、菜单/数据串端的问题
- 企业端「我的」页补「切换到求职端」入口（setRole('candidate') + replace /(tabs)/jobs），
  与求职端「切换到企业端」对称，避免经设置进入企业端后回不去
- 求职端「切换到企业端」卡片 onPress 显式 setRole('enterprise') 兜底

app/(enterprise)/_layout.tsx

@@ -1,7 +1,8 @@
 import { Ionicons } from '@expo/vector-icons';
 import { Tabs } from 'expo-router/js-tabs';
 import type { BottomTabBarProps } from 'expo-router/js-tabs';
-import { useEffect, useRef } from 'react';
+import { useFocusEffect } from 'expo-router';
+import { useCallback, useEffect, useRef } from 'react';
 import { Animated, Easing, Pressable, StyleSheet, View } from 'react-native';
 import { colors } from '../../src/theme';
 import { useRole } from '../../src/context/RoleContext';
@@ -142,9 +143,13 @@ function TabBar({ state, descriptors, navigation, insets }: BottomTabBarProps) {
 export default function EnterpriseTabLayout() {
   const { setRole } = useRole();
 
-  useEffect(() => {
+  // 用 useFocusEffect：进入/返回该端时随焦点写入角色，
+  // 避免「切换到企业端」后返回时 layout 未重新挂载导致 role 残留 candidate。
+  useFocusEffect(
+    useCallback(() => {
       setRole('enterprise');
-  }, [setRole]);
+    }, [setRole]),
+  );
 
   return (
     <Tabs

app/(enterprise)/enterprise-overview.tsx

@@ -11,6 +11,7 @@ import {
 } from 'react-native';
 import { SafeAreaView } from 'react-native-safe-area-context';
 import { useEnterpriseOverview } from '../../src/hooks';
+import { useRole } from '../../src/context/RoleContext';
 import { colors, headerGradient } from '../../src/theme';
 import type { EnterpriseOverview, EnterpriseQuickAction, EnterpriseStat, JobEvaluationSummary, MenuItem } from '../../src/types';
 
@@ -223,6 +224,36 @@ function MenuList({ items }: { items: MenuItem[] }) {
   );
 }
 
+/* ===================== 子组件：切换到求职端卡片 ===================== */
+
+/**
+ * 企业端「我的」页回切求职端，与求职端「切换到企业端」卡片对称，
+ * 避免经「设置→身份切换」进入企业端后返回栈为空、回不去求职端。
+ */
+function CandidateEntryCard() {
+  const router = useRouter();
+  const { setRole } = useRole();
+  return (
+    <Pressable
+      style={styles.candidateCard}
+      onPress={() => {
+        setRole('candidate');
+        router.replace('/(tabs)/jobs');
+      }}
+      hitSlop={4}
+    >
+      <View style={styles.candidateIconWrap}>
+        <Ionicons name="person-outline" size={22} color={colors.primary} />
+      </View>
+      <View style={styles.candidateText}>
+        <Text style={styles.candidateTitle}>切换到求职端</Text>
+        <Text style={styles.candidateDesc}>返回求职者端，浏览岗位与你的竞争力数据</Text>
+      </View>
+      <Text style={styles.candidateAction}>去求职端 →</Text>
+    </Pressable>
+  );
+}
+
 /* ===================== 页面主组件 ===================== */
 
 export default function EnterpriseOverviewScreen() {
@@ -254,6 +285,7 @@ export default function EnterpriseOverviewScreen() {
         </SafeAreaView>
       </LinearGradient>
       <ScrollView style={styles.scroll} contentContainerStyle={styles.scrollContent}>
+        <CandidateEntryCard />
         <StatGrid stats={overview.stats} />
         <QuickActions actions={overview.quickActions} />
         <JobEvaluationList jobs={overview.jobEvaluations} />
@@ -520,4 +552,45 @@ const styles = StyleSheet.create({
     fontWeight: '500',
     color: colors.textPrimary,
   },
+  candidateCard: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    backgroundColor: colors.white,
+    borderRadius: 16,
+    padding: 16,
+    marginBottom: 16,
+    shadowColor: colors.shadow,
+    shadowOffset: { width: 0, height: 2 },
+    shadowOpacity: 0.04,
+    shadowRadius: 6,
+    elevation: 2,
+  },
+  candidateIconWrap: {
+    width: 44,
+    height: 44,
+    borderRadius: 12,
+    backgroundColor: colors.primaryLight,
+    justifyContent: 'center',
+    alignItems: 'center',
+    marginRight: 12,
+  },
+  candidateText: {
+    flex: 1,
+  },
+  candidateTitle: {
+    fontSize: 15,
+    fontWeight: '600',
+    color: colors.textPrimary,
+    marginBottom: 2,
+  },
+  candidateDesc: {
+    fontSize: 12,
+    color: colors.textSecondary,
+  },
+  candidateAction: {
+    fontSize: 13,
+    fontWeight: '600',
+    color: colors.primary,
+    marginLeft: 8,
+  },
 });

app/(tabs)/_layout.tsx

@@ -1,7 +1,8 @@
 import { Ionicons } from '@expo/vector-icons';
 import { Tabs } from 'expo-router/js-tabs';
 import type { BottomTabBarProps } from 'expo-router/js-tabs';
-import { useEffect, useRef } from 'react';
+import { useFocusEffect } from 'expo-router';
+import { useCallback, useEffect, useRef } from 'react';
 import { Animated, Easing, Pressable, StyleSheet, View } from 'react-native';
 import { colors } from '../../src/theme';
 import { useRole } from '../../src/context/RoleContext';
@@ -164,9 +165,13 @@ function TabBar({ state, descriptors, navigation, insets }: BottomTabBarProps) {
 export default function TabLayout() {
   const { setRole } = useRole();
 
-  useEffect(() => {
+  // 用 useFocusEffect：进入/返回该端时随焦点写入角色，
+  // 避免「从企业端返回求职端」时 layout 未重新挂载导致 role 残留 enterprise。
+  useFocusEffect(
+    useCallback(() => {
       setRole('candidate');
-  }, [setRole]);
+    }, [setRole]),
+  );
 
   return (
     <Tabs

app/(tabs)/profile.tsx

@@ -149,8 +149,16 @@ function StatsRow({ stats }: { stats: UserStats }) {
 /** 切换到企业端卡片 */
 function EnterpriseEntryCard({ entry }: { entry: EnterpriseEntry }) {
   const router = useRouter();
+  const { setRole } = useRole();
   return (
-    <Pressable style={styles.enterpriseCard} onPress={() => router.push('/enterprise-overview')}>
+    <Pressable
+      style={styles.enterpriseCard}
+      onPress={() => {
+        setRole('enterprise');
+        router.push('/enterprise-overview');
+      }}
+      hitSlop={4}
+    >
       <View style={styles.enterpriseIconWrap}>
         <Ionicons name="business-outline" size={22} color={colors.primary} />
       </View>

src/api/api.ts

@@ -3290,7 +3290,7 @@ const MOCK_IDENTITY_OPTIONS: IdentityOption[] = [
     title: '我是企业 / HR',
     desc: '发布岗位、筛选人才、管理评价、展示企业形象',
     icon: 'briefcase-outline',
-    role: 'hr',
+    role: 'enterprise',
   },
 ];
 

src/types/tools.ts

@@ -343,6 +343,6 @@ export interface IdentityOption {
   desc: string;
   /** 图标名（Ionicons） */
   icon: string;
-  /** 角色：求职者 / HR */
-  role: 'candidate' | 'hr';
+  /** 角色：求职者 / 企业(HR) */
+  role: 'candidate' | 'enterprise';
 }