refactor(core): distinguish network errors from auth failures and refactor real-time messaging pipeline

- Add isNetworkError() helper and FetchCurrentUserResult discriminated union to prevent logout on network failures
- Refactor authService to return { kind: 'user' } | { kind: 'auth_failed' } | { kind: 'network_error' }
- Update authStore to preserve login state on network errors, only logout on auth failures
- Replace WSMessageHandler with RealtimeIngestionPipeline for improved real-time message handling
- Remove MessageDeduplication service; add store-level idempotent addOrReplaceMessage for message dedup
- Add atomic systemUnreadCount operations to prevent race conditions
- Add SearchHeader component for consistent search UI across screens
- Add 'home' TabBar variant with underline style matching HomeScreen
- Add Jest test infrastructure and exclude tests from tsconfig
- Fix ChatScreen history lock being stuck when scrolling to latest messages
- Remove unused call_participant_joined/left WS event types

src/screens/home/SearchScreen.tsx

@@ -24,7 +24,7 @@ import { useUserStore } from '../../stores';
 import { postService, authService } from '../../services';
 import { tradeService } from '../../services/trade/tradeService';
 import { postSyncService } from '@/services/post';
-import { PostCard, SearchBar } from '../../components/business';
+import { PostCard, SearchHeader, TabBar } from '../../components/business';
 import { TradeCard } from '../../components/business/TradeCard/TradeCard';
 import type { PostCardAction } from '../../components/business/PostCard';
 import { Avatar, EmptyState, Text, ResponsiveGrid, Loading } from '../../components/common';
@@ -601,66 +601,32 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, homeTab = 's
 
   return (
     <SafeAreaView style={styles.container} edges={['top', 'bottom']}>
-      {/* 搜索输入框 */}
-      <View
-        style={[
-          styles.searchHeader,
-          {
-            paddingTop: spacing.sm,
-            paddingHorizontal: responsivePadding,
-            paddingBottom: spacing.xs,
-          },
-        ]}
-      >
-        <View style={[styles.searchShell, { maxWidth: searchBarMaxWidth }]}>
-          <SearchBar
-            value={searchText}
-            onChangeText={setSearchText}
-            onSubmit={handleSearch}
-            placeholder={isMarket ? "搜索商品、用户" : "搜索帖子、用户"}
-            autoFocus
-            compact
-          />
-        </View>
-        <TouchableOpacity
-          style={[styles.cancelButton, { marginLeft: responsiveGap }]}
-          onPress={() => (onBack ? onBack() : router.back())}
-          activeOpacity={0.85}
-        >
-          <Text 
-            variant="body" 
-            color={colors.primary.main}
-            style={styles.cancelText}
-          >
-            取消
-          </Text>
-        </TouchableOpacity>
-      </View>
+      {/* 搜索顶栏（统一组件，内置硬件返回键拦截） */}
+      <SearchHeader
+        value={searchText}
+        onChangeText={setSearchText}
+        onSubmit={handleSearch}
+        onCancel={onBack ? onBack : () => router.back()}
+        placeholder={isMarket ? "搜索商品、用户" : "搜索帖子、用户"}
+        compact
+        searchBarMaxWidth={searchBarMaxWidth}
+        horizontalPadding={responsivePadding}
+      />
 
       {/* Tab切换 - 与主页风格一致的下划线样式 */}
       <View style={styles.tabWrapper}>
-        <View style={[styles.homeTabSwitcher, { paddingHorizontal: responsivePadding }]}>
-          {TABS.map((tab, index) => {
-            const isActive = activeIndex === index;
-            return (
-              <TouchableOpacity
-                key={tab}
-                activeOpacity={0.7}
-                style={[styles.homeTabItem, isActive && styles.homeTabItemActive]}
-                onPress={() => {
-                  setActiveIndex(index);
-                  if (currentKeyword && hasSearched) {
-                    performSearch(currentKeyword);
-                  }
-                }}
-              >
-                <Text style={isActive ? styles.homeTabTextActive : styles.homeTabText}>
-                  {tab}
-                </Text>
-              </TouchableOpacity>
-            );
-          })}
-        </View>
+        <TabBar
+          tabs={TABS}
+          activeIndex={activeIndex}
+          onTabChange={(index) => {
+            setActiveIndex(index);
+            if (currentKeyword && hasSearched) {
+              performSearch(currentKeyword);
+            }
+          }}
+          variant="home"
+          style={{ paddingHorizontal: responsivePadding }}
+        />
       </View>
 
       {/* 内容区域 */}
@@ -675,52 +641,10 @@ function createSearchScreenStyles(colors: AppColors) {
       flex: 1,
       backgroundColor: colors.background.default,
     },
-    searchHeader: {
-      flexDirection: 'row',
-      alignItems: 'center',
-      backgroundColor: colors.background.default,
-    },
-    searchShell: {
-      flex: 1,
-    },
-    cancelButton: {
-      borderRadius: borderRadius.full,
-      paddingHorizontal: spacing.md,
-      paddingVertical: spacing.sm,
-    },
-    cancelText: {
-      fontSize: fontSizes.md,
-      fontWeight: '600',
-    },
     tabWrapper: {
       backgroundColor: colors.background.default,
       paddingVertical: spacing.xs,
     },
-    homeTabSwitcher: {
-      flexDirection: 'row',
-      alignItems: 'center',
-      gap: 20,
-    },
-    homeTabItem: {
-      paddingVertical: spacing.sm,
-      alignItems: 'center',
-      justifyContent: 'center',
-      borderBottomWidth: 2,
-      borderBottomColor: 'transparent',
-    },
-    homeTabItemActive: {
-      borderBottomColor: colors.text.primary,
-    },
-    homeTabText: {
-      fontSize: 18,
-      fontWeight: '400',
-      color: colors.text.hint,
-    },
-    homeTabTextActive: {
-      fontSize: 18,
-      fontWeight: '700',
-      color: colors.text.primary,
-    },
     suggestionsContainer: {
       flex: 1,
     },