feat(auth): enhance login error handling with detailed error code mapping

- Add backend error_code support (INVALID_CREDENTIALS, USER_BANNED, etc.)
- Improve network error detection with code=0 fallback
- Add granular HTTP status code handling (400, 401, 403, 429, 5xx)
- Update LoginScreen to display authStore error or generic message
- Include notification service improvements:
  - Keep JPush connection alive in background via setKeepLongConnInBackground
  - Add manual sound/vibration for local notifications via preferences
- Fix SearchScreen layout by accounting for floating tab bar and safe area

src/screens/auth/LoginScreen.tsx

@@ -107,12 +107,11 @@ export const LoginScreen: React.FC = () => {
     try {
       const success = await login({ username, password });
       if (!success) {
-        if (!useAuthStore.getState().error) {
-          showPrompt({ title: '登录失败', message: '请检查用户名和密码', type: 'error' });
-        }
+        const errorMsg = useAuthStore.getState().error || '登录失败，请稍后重试';
+        showPrompt({ title: '登录失败', message: errorMsg, type: 'error' });
       }
     } catch (error: any) {
-      showPrompt({ title: '登录失败', message: error.message || '请检查用户名和密码', type: 'error' });
+      showPrompt({ title: '登录失败', message: error.message || '登录失败，请稍后重试', type: 'error' });
     } finally {
       setLoading(false);
     }

src/screens/home/SearchScreen.tsx

@@ -13,7 +13,7 @@ import {
   ScrollView,
   RefreshControl,
 } from 'react-native';
-import { SafeAreaView } from 'react-native-safe-area-context';
+import { SafeAreaView, useSafeAreaInsets } from 'react-native-safe-area-context';
 import { useRouter } from 'expo-router';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
 import { spacing, fontSizes, borderRadius, useAppColors, type AppColors } from '../../theme';
@@ -30,6 +30,8 @@ import { useCursorPagination } from '../../hooks/useCursorPagination';
 
 const TABS = ['帖子', '用户'];
 const DEFAULT_PAGE_SIZE = 20;
+// 与 TabsLayout 中的常量保持一致：tabBarHeight 56 + 上下浮动间距 12*2
+const FLOATING_TAB_BAR_HEIGHT = 56 + 12 * 2;
 
 type SearchType = 'posts' | 'users';
 
@@ -41,6 +43,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
   const colors = useAppColors();
   const styles = useMemo(() => createSearchScreenStyles(colors), [colors]);
   const router = useRouter();
+  const insets = useSafeAreaInsets();
   const { searchHistory: history, addSearchHistory, clearSearchHistory } = useUserStore();
   
   // 使用响应式 hook
@@ -73,6 +76,9 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
     '4xl': 1200,
   });
   
+  // 底部预留空间：悬浮 TabBar 高度 + 底部安全区 + 间距
+  const listBottomInset = FLOATING_TAB_BAR_HEIGHT + insets.bottom + spacing.md;
+
   const [searchText, setSearchText] = useState('');
   const [activeIndex, setActiveIndex] = useState(0);
   const [hasSearched, setHasSearched] = useState(false);
@@ -238,7 +244,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
       return (
         <ScrollView 
           showsVerticalScrollIndicator={false}
-          contentContainerStyle={{ paddingBottom: responsivePadding }}
+          contentContainerStyle={{ paddingBottom: listBottomInset }}
           refreshControl={
             <RefreshControl
               refreshing={isRefreshing}
@@ -287,7 +293,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
           />
         )}
         keyExtractor={item => item.id}
-        contentContainerStyle={{ paddingBottom: responsivePadding }}
+        contentContainerStyle={{ paddingBottom: listBottomInset }}
         showsVerticalScrollIndicator={false}
         refreshControl={
           <RefreshControl
@@ -323,7 +329,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
       return (
         <ScrollView 
           showsVerticalScrollIndicator={false}
-          contentContainerStyle={{ paddingBottom: responsivePadding }}
+          contentContainerStyle={{ paddingBottom: listBottomInset }}
         >
           <ResponsiveGrid
             columns={{ xs: 1, sm: 2, md: 2, lg: 3, xl: 3, '2xl': 4, '3xl': 4, '4xl': 5 }}
@@ -412,7 +418,7 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack }) => {
           </TouchableOpacity>
         )}
         keyExtractor={item => item.id}
-        contentContainerStyle={{ paddingVertical: responsiveGap }}
+        contentContainerStyle={{ paddingVertical: responsiveGap, paddingBottom: listBottomInset }}
         showsVerticalScrollIndicator={false}
         ListFooterComponent={userLoading ? <Loading size="sm" /> : null}
       />

src/services/notification/jpushService.ts

@@ -1,4 +1,4 @@
-import { Platform, NativeModules, AppState } from 'react-native';
+import { Platform, NativeModules, AppState, Vibration } from 'react-native';
 import { pushService } from './pushService';
 import * as Notifications from 'expo-notifications';
 import { getNotificationPreferencesSync } from './notificationPreferences';
@@ -112,6 +112,9 @@ class JPushService {
       // Register listeners only once (idempotent guard)
       this._registerListeners();
 
+      // 退后台保持极光长连接，确保推送实时到达
+      this._setBackgroundKeepLongConn(true);
+
       // 初始化 SDK
       JPush!.init({
         appKey: jpushAppKey,
@@ -165,12 +168,12 @@ class JPushService {
       console.warn('[JPush] setChannelAndSound failed:', error);
     }
 
+    // Ensure notification channel has sound & vibration enabled via expo-notifications
     try {
       Notifications.setNotificationChannelAsync('jpush_notification', {
         name: '推送通知',
         importance: Notifications.AndroidImportance.HIGH,
         vibrationPattern: [0, 250, 250, 250],
-        sound: 'default',
         enableLights: true,
         showBadge: true,
       });
@@ -179,6 +182,30 @@ class JPushService {
     }
   }
 
+  /**
+   * 设置退后台是否保持极光长连接
+   * @see https://docs.jiguang.cn/jpush/client/Android/android_api#退后台是否保持极光长连接-api
+   */
+  private _setBackgroundKeepLongConn(keep: boolean): void {
+    if (!JPush) return;
+    try {
+      if (Platform.OS === 'android') {
+        const jpushModule = NativeModules.JPushModule;
+        if (jpushModule?.setKeepLongConnInBackground) {
+          jpushModule.setKeepLongConnInBackground(keep);
+          console.log('[JPush] setKeepLongConnInBackground:', keep);
+        } else {
+          console.warn('[JPush] setKeepLongConnInBackground not available in native module');
+        }
+      } else if (Platform.OS === 'ios') {
+        JPush.setBackgroundEnable(keep);
+        console.log('[JPush] setBackgroundEnable:', keep);
+      }
+    } catch (error) {
+      console.warn('[JPush] setBackgroundKeepLongConn failed:', error);
+    }
+  }
+
   private _fetchRegistrationID(): void {
     if (!JPush) return;
     JPush.getRegistrationID((result: any) => {
@@ -329,6 +356,21 @@ class JPushService {
       } else {
         JPush.addLocalNotification(params);
       }
+
+      // JPush local notification does not support sound/vibration directly.
+      // Trigger them manually based on user preferences.
+      const prefs = getNotificationPreferencesSync();
+      if (prefs.soundEnabled) {
+        // Play system default notification sound via a silent expo-notification
+        Notifications.scheduleNotificationAsync({
+          content: { title: '', body: '', sound: true, vibrate: [] },
+          trigger: null,
+        }).catch(() => {});
+      }
+      if (prefs.vibrationEnabled) {
+        // Use React Native Vibration API for device-level vibration
+        Vibration.vibrate([0, 250, 250, 250]);
+      }
     } catch (error) {
       console.error('[JPush] addLocalNotification failed:', error);
     }

src/services/notification/systemNotificationService.ts

@@ -208,9 +208,6 @@ class SystemNotificationService {
 
   async clearAllNotifications(): Promise<void> {
     jpushService.clearAllNotifications();
-    if (Platform.OS === 'web' && 'Notification' in window) {
-      // No programmatic way to clear browser notifications
-    }
   }
 
   async clearBadge(): Promise<void> {

src/stores/auth/authStore.ts

@@ -62,32 +62,61 @@ async function cacheUser(user: User): Promise<void> {
 }
 
 // ── 将 API 错误转换为用户可读的中文提示 ──
+// 优先使用后端返回的 error_code 精确匹配，兜底使用 HTTP 状态码和 message
 function resolveLoginError(error: any): string {
   const code: number = error?.code ?? 0;
-  const msg: string = error?.message ?? '';
+  const msg: string = String(error?.message ?? '');
+  const errorCode: string = String(error?.errorCode ?? '').toUpperCase();
 
-  // 网络层错误（无法连接服务器）
+  // 网络层错误（无法连接服务器）—— code 为 0 通常是请求未发出
   if (
+    code === 0 ||
     msg.includes('Network request failed') ||
     msg.includes('网络请求失败') ||
-    msg.includes('Failed to fetch') ||
-    code === 500
+    msg.includes('Failed to fetch')
   ) {
     return '无法连接到服务器，请检查网络连接后重试';
   }
 
-  // 账号或密码错误
-  if (code === 401 || msg.includes('密码') || msg.includes('用户名') || msg.includes('incorrect')) {
+  // 优先使用后端 error_code 精确匹配
+  switch (errorCode) {
+    case 'INVALID_CREDENTIALS':
+      return '用户名或密码错误，请重新输入';
+    case 'USER_BANNED':
+      return '账号已被封禁，请联系管理员';
+    case 'USER_BLOCKED':
+      return '该账号存在异常，暂时无法登录';
+    case 'USER_NOT_FOUND':
+      return '用户不存在，请检查输入';
+    case 'BAD_REQUEST':
+      return '请求参数有误，请检查输入';
+    case 'UNAUTHORIZED':
+      return '登录已过期，请重新登录';
+    case 'FORBIDDEN':
+      return '没有访问权限，请联系管理员';
+    case 'INTERNAL_ERROR':
+      return '服务器内部错误，请稍后重试';
+    case 'TOO_MANY_REQUESTS':
+    case 'RATE_LIMITED':
+      return '登录尝试过于频繁，请稍后再试';
+  }
+
+  // 兜底：按 HTTP 状态码分类
+  if (code === 401 || code === 400) {
     return '用户名或密码错误，请重新输入';
   }
-
-  // 账号被禁用/封禁
-  if (code === 403 || msg.includes('禁止') || msg.includes('封禁') || msg.includes('forbidden')) {
+  if (code === 403) {
     return '账号已被禁用，请联系管理员';
   }
+  if (code === 429) {
+    return '登录尝试过于频繁，请稍后再试';
+  }
+  if (code >= 500) {
+    return '服务器开小差了，请稍后重试';
+  }
 
-  // 服务端明确返回了 message，直接用
-  if (msg && msg !== '登录失败') {
+  // 最后兜底：如果后端返回了有意义的 message，直接用
+  if (msg && msg !== '登录失败' && msg !== '请求失败') {
     return msg;
   }