新增：首页 Feed 接入真实数据——四态/尾部三态/聚合曝光埋点，社区 demo 消亡第一页（T3-14）

- home_page Feed segment 改接 CommunityController：骨架屏首载、空态 CTA、
  错误横幅重试、下拉刷新（失败保留旧列表 + SnackBar）、触底游标翻页
  （失败态只走显式重试，不随滚动风暴自动重打）
- PostCard 三形态（单图通栏 4:3 / 多图折叠封面 +N 角标 / 纯文字 6 行）+
  PostMediaGrid（列数规则 + ink 80% scrim 精算）+ LikeButton（error 族修订
  Colors.red，T3-14 纯展示禁用态，ToggleSync 接线留 T3-15/16）+ FeedSkeleton
  （呼吸动效尊重减弱动态设置）；降级作者统一「宠友」占位
- SignedNetworkImage：预签名 URL 缓存 key 剥离 X-Amz-* 签名参数，
  RemoteImage 全仓换用（同图不同签名命中同一缓存条目）
- feed 域埋点：feed_viewed 聚合曝光（浏览段开/结算于切 Tab、切分段、
  退后台、销毁；≥50% 可见 ≥500ms 段内按帖去重，postId 不上报）+
  feed_load_failed（refresh/load_more 双路，会话失效不报）
- integration_test/feed_live_test.dart：compose 六容器 Linux 桌面真链路
  实测入口（PATBOND_FEED_LIVE=1 门控，默认跳过）
- 测试 379 → 421（+42）：四态/尾部三态/翻页不丢不重/降级作者/曝光结算
  时机/缓存 key/事件属性全覆盖；analyze 0，format 无 diff

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/core/network/signed_network_image_test.dart

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+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/network/signed_network_image.dart';
+
+void main() {
+  group('presignedImageCacheKey', () {
+    test('剥离全部 X-Amz-* 签名参数（大小写不敏感）', () {
+      const url =
+          'http://127.0.0.1:9000/patbond-media/post_image/a-1.jpg'
+          '?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=cred'
+          '&X-Amz-Date=20260909T000000Z&X-Amz-Expires=3600'
+          '&X-Amz-SignedHeaders=host&x-amz-signature=deadbeef';
+      expect(
+        presignedImageCacheKey(url),
+        'http://127.0.0.1:9000/patbond-media/post_image/a-1.jpg',
+      );
+    });
+
+    test('保留非签名 query 参数', () {
+      const url = 'https://cdn.example.com/p.jpg?w=300&X-Amz-Signature=sig';
+      expect(
+        presignedImageCacheKey(url),
+        'https://cdn.example.com/p.jpg?w=300',
+      );
+    });
+
+    test('无签名参数原样返回', () {
+      expect(
+        presignedImageCacheKey('https://cdn.example.com/p.jpg?w=300&q=80'),
+        'https://cdn.example.com/p.jpg?w=300&q=80',
+      );
+      expect(
+        presignedImageCacheKey('https://cdn.example.com/p.jpg'),
+        'https://cdn.example.com/p.jpg',
+      );
+    });
+
+    test('非法 URL 不炸，退回原串', () {
+      expect(presignedImageCacheKey('::not a url::'), '::not a url::');
+    });
+  });
+
+  group('SignedNetworkImage', () {
+    test('同对象不同签名 → 判等（命中同一 ImageCache 条目）', () {
+      final first = SignedNetworkImage(
+        'http://127.0.0.1:9000/m/a.jpg?X-Amz-Signature=sig1&X-Amz-Date=d1',
+      );
+      final second = SignedNetworkImage(
+        'http://127.0.0.1:9000/m/a.jpg?X-Amz-Signature=sig2&X-Amz-Date=d2',
+      );
+      expect(first, second);
+      expect(first.hashCode, second.hashCode);
+    });
+
+    test('不同对象 → 不判等', () {
+      final first = SignedNetworkImage(
+        'http://127.0.0.1:9000/m/a.jpg?X-Amz-Signature=sig',
+      );
+      final second = SignedNetworkImage(
+        'http://127.0.0.1:9000/m/b.jpg?X-Amz-Signature=sig',
+      );
+      expect(first, isNot(second));
+    });
+
+    test('scale 参与判等', () {
+      final first = SignedNetworkImage('http://h/m/a.jpg');
+      final second = SignedNetworkImage('http://h/m/a.jpg', scale: 2);
+      expect(first, isNot(second));
+    });
+  });
+}

test/core/widgets/post_card_test.dart

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+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/theme/app_theme.dart';
+import 'package:patbond_flutter/core/widgets/like_button.dart';
+import 'package:patbond_flutter/core/widgets/post_card.dart';
+import 'package:patbond_flutter/core/widgets/post_media_grid.dart';
+import 'package:patbond_flutter/features/community/community_models.dart';
+import 'package:patbond_flutter/widgets/common.dart';
+
+import '../../helpers/community_test_helpers.dart';
+
+FeedCard cardFrom(Map<String, dynamic> overrides) =>
+    FeedCard.fromJson({...sampleFeedCardJson(), ...overrides});
+
+Widget wrap(Widget child) => MaterialApp(
+  theme: buildAppTheme(),
+  home: Scaffold(body: SingleChildScrollView(child: child)),
+);
+
+void main() {
+  testWidgets('单图形态：通栏 4:3 出血，不走九宫格，预览 2 行', (tester) async {
+    final card = cardFrom({'mediaCount': 1});
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.byType(AspectRatio), findsOneWidget);
+    expect(find.byType(PostMediaGrid), findsNothing);
+    final preview = tester.widget<Text>(find.text('晒了一下午太阳。'));
+    expect(preview.maxLines, 2);
+  });
+
+  testWidgets('多图形态：九宫格折叠封面 + 「+N」角标（契约只带封面与计数）', (tester) async {
+    final card = cardFrom({'mediaCount': 5});
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.byType(PostMediaGrid), findsOneWidget);
+    expect(find.text('+4'), findsOneWidget);
+  });
+
+  testWidgets('纯文字形态：无媒体区，正文放宽 6 行、15/1.6', (tester) async {
+    final card = cardFrom({'coverImage': null, 'mediaCount': 0});
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.byType(PostMediaGrid), findsNothing);
+    expect(find.byType(AspectRatio), findsNothing);
+    final preview = tester.widget<Text>(find.text('晒了一下午太阳。'));
+    expect(preview.maxLines, 6);
+    expect(preview.style?.fontSize, 15);
+  });
+
+  testWidgets('头部行：作者名 + 相对时间；求助帖追加 accent 标', (tester) async {
+    final card = cardFrom({
+      'category': 'help',
+      'publishedAt': DateTime.now()
+          .subtract(const Duration(hours: 2))
+          .toUtc()
+          .toIso8601String(),
+    });
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.text('毛毛的铲屎官'), findsOneWidget);
+    expect(find.text('2 小时前'), findsOneWidget);
+    expect(find.widgetWithText(TagPill, '求助'), findsOneWidget);
+  });
+
+  testWidgets('降级作者：占位头像 + 「宠友」默认名', (tester) async {
+    final card = cardFrom({
+      'author': sampleAuthorJson(nickname: null, avatarUrl: null),
+    });
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.text('宠友'), findsOneWidget);
+    expect(find.text('毛毛的铲屎官'), findsNothing);
+  });
+
+  testWidgets('操作行：计数与激活态展示；T3-14 纯展示点按无副作用', (tester) async {
+    final card = cardFrom({
+      'likedByMe': true,
+      'likeCount': 6,
+      'bookmarkedByMe': false,
+      'bookmarkCount': 2,
+      'commentCount': 3,
+    });
+    await tester.pumpWidget(wrap(PostCard(card: card)));
+
+    expect(find.text('6'), findsOneWidget);
+    expect(find.text('2'), findsOneWidget);
+    expect(find.text('3'), findsOneWidget);
+    // 点赞激活：实心 favorite + error 色（Colors.red 修订 D6）。
+    final likeIcon = tester.widget<Icon>(find.byIcon(Icons.favorite));
+    expect(likeIcon.color, AppColors.error);
+    // 收藏未激活：描边 + inkSoft。
+    final bookmarkIcon = tester.widget<Icon>(
+      find.byIcon(Icons.bookmark_border),
+    );
+    expect(bookmarkIcon.color, AppColors.inkSoft);
+
+    // 回调未接（null）：点按不抛错、无状态变化。
+    await tester.tap(find.byType(LikeButton).first, warnIfMissed: false);
+    await tester.pump();
+    expect(find.byIcon(Icons.favorite), findsOneWidget);
+  });
+}

test/core/widgets/post_media_grid_test.dart

@@ -0,0 +1,100 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/theme/app_theme.dart';
+import 'package:patbond_flutter/core/widgets/feed_skeleton.dart';
+import 'package:patbond_flutter/core/widgets/post_media_grid.dart';
+import 'package:patbond_flutter/widgets/common.dart';
+
+Widget wrap(Widget child, {bool disableAnimations = false}) => MaterialApp(
+  theme: buildAppTheme(),
+  home: MediaQuery(
+    data: MediaQueryData(disableAnimations: disableAnimations),
+    child: Scaffold(body: SingleChildScrollView(child: child)),
+  ),
+);
+
+List<String> urls(int count) => List.generate(
+  count,
+  (i) => 'https://minio.local/p$i.jpg?X-Amz-Signature=s',
+);
+
+void main() {
+  group('PostMediaGrid 列数规则（05 §3.2）', () {
+    test('2、4 图 → 2 列；3、5–9 图 → 3 列', () {
+      expect(PostMediaGrid.columnsFor(2), 2);
+      expect(PostMediaGrid.columnsFor(4), 2);
+      expect(PostMediaGrid.columnsFor(3), 3);
+      for (var n = 5; n <= 9; n++) {
+        expect(PostMediaGrid.columnsFor(n), 3);
+      }
+    });
+
+    testWidgets('4 图渲染 4 格网格', (tester) async {
+      await tester.pumpWidget(wrap(PostMediaGrid(urls: urls(4))));
+      expect(find.byType(RemoteImage), findsNWidgets(4));
+      expect(find.byType(GridView), findsOneWidget);
+    });
+
+    testWidgets('超 9 图折叠：显 9 格，末格 ink 80% scrim + 「+N」', (tester) async {
+      await tester.pumpWidget(
+        wrap(PostMediaGrid(urls: urls(12), totalCount: 12)),
+      );
+      expect(find.byType(RemoteImage), findsNWidgets(9));
+      expect(find.text('+3'), findsOneWidget);
+      final scrim = tester
+          .widgetList<DecoratedBox>(find.byType(DecoratedBox))
+          .map((w) => w.decoration)
+          .whereType<BoxDecoration>()
+          .where((d) => d.color == AppColors.ink.withAlpha(204));
+      expect(scrim, isNotEmpty);
+    });
+
+    testWidgets('单图折叠形态（Feed 封面 + 总数）：4:3 单格 + 角标胶囊', (tester) async {
+      await tester.pumpWidget(
+        wrap(PostMediaGrid(urls: urls(1), totalCount: 3)),
+      );
+      expect(find.byType(GridView), findsNothing);
+      expect(find.byType(AspectRatio), findsOneWidget);
+      expect(find.text('+2'), findsOneWidget);
+    });
+
+    testWidgets('单图无折余不出角标', (tester) async {
+      await tester.pumpWidget(wrap(PostMediaGrid(urls: urls(1))));
+      expect(find.textContaining('+'), findsNothing);
+    });
+  });
+
+  group('FeedSkeleton（05 §3.7）', () {
+    testWidgets('骨架单元：头部圆 + 4:3 块 + 正文横条，呼吸动效运行', (tester) async {
+      await tester.pumpWidget(wrap(const FeedSkeleton()));
+      await tester.pump(const Duration(milliseconds: 300));
+      expect(find.byType(AspectRatio), findsOneWidget);
+      final fade = tester.widget<FadeTransition>(
+        find
+            .descendant(
+              of: find.byType(FeedSkeleton),
+              matching: find.byType(FadeTransition),
+            )
+            .first,
+      );
+      final controller = fade.opacity as AnimationController;
+      expect(controller.isAnimating, isTrue);
+    });
+
+    testWidgets('系统减弱动态效果：动画静止在 1.0（pumpAndSettle 可收敛）', (tester) async {
+      await tester.pumpWidget(
+        wrap(const FeedSkeleton(), disableAnimations: true),
+      );
+      await tester.pumpAndSettle();
+      final fade = tester.widget<FadeTransition>(
+        find
+            .descendant(
+              of: find.byType(FeedSkeleton),
+              matching: find.byType(FadeTransition),
+            )
+            .first,
+      );
+      expect(fade.opacity.value, 1.0);
+    });
+  });
+}

test/features/community/feed_analytics_test.dart

@@ -0,0 +1,92 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/network/api_exception.dart';
+import 'package:patbond_flutter/features/community/feed_analytics.dart';
+
+void main() {
+  late List<(String, Map<String, dynamic>?)> events;
+  late FeedAnalytics analytics;
+
+  setUp(() {
+    events = [];
+    analytics = FeedAnalytics(
+      (name, [props]) async => events.add((name, props)),
+    );
+  });
+
+  test('feed_viewed：五个专有属性逐一上报（06 §1.4 白名单）', () {
+    analytics.feedViewed(
+      feedTab: FeedTab.home,
+      durationMs: 12345,
+      impressionCount: 7,
+      loadMoreCount: 2,
+      refreshCount: 1,
+    );
+
+    expect(events, hasLength(1));
+    expect(events.single.$1, 'feed_viewed');
+    expect(events.single.$2, {
+      'feedTab': 'home',
+      'durationMs': 12345,
+      'impressionCount': 7,
+      'loadMoreCount': 2,
+      'refreshCount': 1,
+    });
+  });
+
+  test('feed_load_failed：业务码带 errorCode 并推导 httpStatus', () {
+    analytics.feedLoadFailed(
+      feedTab: FeedTab.home,
+      loadType: FeedLoadType.loadMore,
+      reason: FeedLoadFailureReason.serverError,
+      errorCode: 40403,
+    );
+
+    expect(events.single.$1, 'feed_load_failed');
+    expect(events.single.$2, {
+      'feedTab': 'home',
+      'loadType': 'load_more',
+      'failureReason': 'server_error',
+      'errorCode': 40403,
+      'httpStatus': 404,
+    });
+  });
+
+  test('feed_load_failed：网络错误缺席 errorCode/httpStatus', () {
+    analytics.feedLoadFailedFrom(
+      const ApiNetworkException(),
+      feedTab: FeedTab.home,
+      loadType: FeedLoadType.refresh,
+    );
+
+    expect(events.single.$2, {
+      'feedTab': 'home',
+      'loadType': 'refresh',
+      'failureReason': 'network_error',
+    });
+  });
+
+  test('异常映射：限流/网络/业务兜底；会话失效不上报', () {
+    expect(
+      feedLoadFailureReasonOf(const ApiRateLimitException()),
+      FeedLoadFailureReason.rateLimited,
+    );
+    expect(
+      feedLoadFailureReasonOf(const ApiNetworkException()),
+      FeedLoadFailureReason.networkError,
+    );
+    expect(
+      feedLoadFailureReasonOf(
+        const ApiBusinessException(code: 40000, message: 'x'),
+      ),
+      FeedLoadFailureReason.serverError,
+    );
+    expect(feedLoadFailureReasonOf(const SessionExpiredException()), isNull);
+
+    analytics.feedLoadFailedFrom(
+      const SessionExpiredException(),
+      feedTab: FeedTab.home,
+      loadType: FeedLoadType.refresh,
+    );
+    expect(events, isEmpty);
+  });
+}

test/features/community/feed_exposure_test.dart

@@ -0,0 +1,77 @@
+import 'package:fake_async/fake_async.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/features/community/feed_exposure.dart';
+
+void main() {
+  test('曝光判定：≥50% 驻留满 500ms 记一次，段内按帖去重', () {
+    fakeAsync((async) {
+      final segment = FeedViewSegment(now: async.getClock(DateTime(2026)).now);
+      segment.updateVisibility('p-1', 0.8);
+      async.elapse(const Duration(milliseconds: 600));
+      expect(segment.impressionCount, 1);
+
+      // 再次可见不重复计。
+      segment.updateVisibility('p-1', 0.9);
+      async.elapse(const Duration(milliseconds: 600));
+      expect(segment.impressionCount, 1);
+    });
+  });
+
+  test('快速滑过（<500ms 跌破阈值）不计曝光', () {
+    fakeAsync((async) {
+      final segment = FeedViewSegment(now: async.getClock(DateTime(2026)).now);
+      segment.updateVisibility('p-1', 0.8);
+      async.elapse(const Duration(milliseconds: 300));
+      segment.updateVisibility('p-1', 0.2); // 滚出视口
+      async.elapse(const Duration(seconds: 1));
+      expect(segment.impressionCount, 0);
+    });
+  });
+
+  test('可见面积不足 50% 不起计时', () {
+    fakeAsync((async) {
+      final segment = FeedViewSegment(now: async.getClock(DateTime(2026)).now);
+      segment.updateVisibility('p-1', 0.49);
+      async.elapse(const Duration(seconds: 1));
+      expect(segment.impressionCount, 0);
+    });
+  });
+
+  test('结算：冻结计数、取消在途驻留、幂等只出一份', () {
+    fakeAsync((async) {
+      final clock = async.getClock(DateTime(2026));
+      final segment = FeedViewSegment(now: clock.now);
+      segment.updateVisibility('p-1', 1);
+      async.elapse(const Duration(milliseconds: 600));
+      segment.updateVisibility('p-2', 1); // 在途驻留，结算时未满 500ms
+      async.elapse(const Duration(milliseconds: 100));
+      segment.recordRefresh();
+      segment.recordLoadMore();
+      segment.recordLoadMore();
+
+      final summary = segment.settle();
+      expect(summary, isNotNull);
+      expect(summary!.impressionCount, 1);
+      expect(summary.refreshCount, 1);
+      expect(summary.loadMoreCount, 2);
+      expect(summary.durationMs, 700);
+
+      // 幂等：二次结算无第二条；结算后计数与曝光全部作废。
+      expect(segment.settle(), isNull);
+      segment.updateVisibility('p-3', 1);
+      async.elapse(const Duration(seconds: 1));
+      expect(segment.impressionCount, 1);
+    });
+  });
+
+  test('durationMs 上限截断 30 分钟（防挂机污染 H8）', () {
+    fakeAsync((async) {
+      final segment = FeedViewSegment(now: async.getClock(DateTime(2026)).now);
+      async.elapse(const Duration(minutes: 45));
+      expect(
+        segment.settle()!.durationMs,
+        const Duration(minutes: 30).inMilliseconds,
+      );
+    });
+  });
+}

test/features/home/home_page_test.dart

@@ -0,0 +1,393 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/network/api_exception.dart';
+import 'package:patbond_flutter/core/theme/app_theme.dart';
+import 'package:patbond_flutter/core/widgets/feed_skeleton.dart';
+import 'package:patbond_flutter/core/widgets/inline_error_banner.dart';
+import 'package:patbond_flutter/core/widgets/post_card.dart';
+import 'package:patbond_flutter/features/community/community_controller.dart';
+import 'package:patbond_flutter/features/community/community_models.dart';
+import 'package:patbond_flutter/features/community/feed_analytics.dart';
+import 'package:patbond_flutter/features/home/home_page.dart';
+import 'package:patbond_flutter/state/app_state.dart';
+
+import '../../helpers/community_test_helpers.dart';
+
+/// 短卡（纯文字）便于视口内多卡曝光断言；内容带 id 便于查重。
+FeedCard textCard(String id) => FeedCard.fromJson({
+  ...sampleFeedCardJson(id: id),
+  'coverImage': null,
+  'mediaCount': 0,
+  'title': null,
+  'contentPreview': '动态内容 $id',
+});
+
+FeedCard degradedCard(String id) => FeedCard.fromJson({
+  ...sampleFeedCardJson(id: id),
+  'coverImage': null,
+  'mediaCount': 0,
+  'title': null,
+  'contentPreview': '动态内容 $id',
+  'author': sampleAuthorJson(nickname: null, avatarUrl: null),
+});
+
+void main() {
+  late FakeCommunityRepository repository;
+  late CommunityController controller;
+  late List<(String, Map<String, dynamic>?)> events;
+  late FeedAnalytics analytics;
+  late int createTaps;
+
+  setUp(() {
+    repository = FakeCommunityRepository();
+    controller = CommunityController(repository: repository);
+    events = [];
+    analytics = FeedAnalytics(
+      (name, [props]) async => events.add((name, props)),
+    );
+    createTaps = 0;
+  });
+
+  List<Map<String, dynamic>?> eventsNamed(String name) =>
+      events.where((e) => e.$1 == name).map((e) => e.$2).toList();
+
+  Future<void> pumpHome(WidgetTester tester, {bool isActive = true}) {
+    return tester.pumpWidget(
+      MaterialApp(
+        theme: buildAppTheme(),
+        home: Scaffold(
+          body: HomePage(
+            appState: AppState(),
+            communityController: controller,
+            feedAnalytics: analytics,
+            isActive: isActive,
+            onOpenServices: (_) {},
+            onOpenCreate: () => createTaps++,
+          ),
+        ),
+      ),
+    );
+  }
+
+  // 页面纵向主列表（story 环是嵌套的水平 ListView，取 first 即外层）。
+  Finder list() => find.byType(ListView).first;
+
+  testWidgets('四态 · loading：首载渲染 3 张骨架屏', (tester) async {
+    final completer = Completer<CursorPage<FeedCard>>();
+    repository.onFeed = (_, _) => completer.future;
+
+    await pumpHome(tester);
+    await tester.pump();
+
+    // 首载骨架连排 3 张（列表懒加载，视口内至少 1 张被实例化）。
+    expect(find.byType(FeedSkeleton), findsAtLeastNWidgets(1));
+
+    completer.complete(feedPage(const []));
+    await tester.pumpAndSettle();
+    expect(find.byType(FeedSkeleton), findsNothing);
+  });
+
+  testWidgets('四态 · empty：空态插画 + 「发布第一条」CTA 去创作', (tester) async {
+    repository.onFeed = (_, _) async => feedPage(const []);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    expect(find.text('还没有动态'), findsOneWidget);
+    await tester.drag(list(), const Offset(0, -300));
+    await tester.pump();
+    await tester.tap(find.text('发布第一条'));
+    expect(createTaps, 1);
+  });
+
+  testWidgets('四态 · error：横幅 + 重试恢复 ready，feed_load_failed 上报', (tester) async {
+    var attempts = 0;
+    repository.onFeed = (_, _) async {
+      attempts += 1;
+      if (attempts == 1) throw const ApiNetworkException();
+      return feedPage([textCard('p-1')]);
+    };
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    expect(find.byType(InlineErrorBanner), findsOneWidget);
+    expect(find.text('网络异常，请检查网络后重试'), findsOneWidget);
+    expect(eventsNamed('feed_load_failed'), [
+      {
+        'feedTab': 'home',
+        'loadType': 'refresh',
+        'failureReason': 'network_error',
+      },
+    ]);
+
+    await tester.drag(list(), const Offset(0, -200));
+    await tester.pump();
+    await tester.tap(find.text('重试'));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(InlineErrorBanner), findsNothing);
+    expect(find.text('动态内容 p-1'), findsOneWidget);
+  });
+
+  testWidgets('四态 · ready：卡片列表 + 降级作者「宠友」占位', (tester) async {
+    repository.onFeed = (_, _) async =>
+        feedPage([textCard('p-1'), degradedCard('p-2')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -400));
+    await tester.pump();
+
+    expect(find.byType(PostCard), findsNWidgets(2));
+    expect(find.text('毛毛的铲屎官'), findsOneWidget);
+    expect(find.text('宠友'), findsOneWidget);
+  });
+
+  testWidgets('翻页：触底携游标加载下一页，不丢不重，到底显「没有更多了」', (tester) async {
+    final page2 = Completer<CursorPage<FeedCard>>();
+    repository.onFeed = (_, cursor) async {
+      if (cursor == null) {
+        return feedPage(
+          [textCard('p-1'), textCard('p-2')],
+          nextCursor: 'c1',
+          hasMore: true,
+        );
+      }
+      return page2.future;
+    };
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    // 触底：尾部 loading 转圈。
+    await tester.drag(list(), const Offset(0, -1000));
+    await tester.pump();
+    expect(find.byType(CircularProgressIndicator), findsOneWidget);
+
+    page2.complete(feedPage([textCard('p-3')]));
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -600));
+    await tester.pump();
+
+    // keyset 游标不丢不重：三帖各恰一张，游标原样带出。
+    expect(repository.calls.where((c) => c.startsWith('feed:')).toList(), [
+      'feed:cursor=null',
+      'feed:cursor=c1',
+    ]);
+    expect(find.text('动态内容 p-1'), findsOneWidget);
+    expect(find.text('动态内容 p-2'), findsOneWidget);
+    expect(find.text('动态内容 p-3'), findsOneWidget);
+    expect(find.text('没有更多了'), findsOneWidget);
+  });
+
+  testWidgets('尾部失败：重试条 + feed_load_failed(load_more)，点按重试补页', (tester) async {
+    var page2Attempts = 0;
+    repository.onFeed = (_, cursor) async {
+      if (cursor == null) {
+        return feedPage([textCard('p-1')], nextCursor: 'c1', hasMore: true);
+      }
+      page2Attempts += 1;
+      if (page2Attempts == 1) {
+        throw const ApiBusinessException(code: 40000, message: 'x');
+      }
+      return feedPage([textCard('p-2')]);
+    };
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -1000));
+    await tester.pumpAndSettle();
+
+    expect(find.text('加载失败，点此重试'), findsOneWidget);
+    expect(eventsNamed('feed_load_failed'), [
+      {
+        'feedTab': 'home',
+        'loadType': 'load_more',
+        'failureReason': 'server_error',
+        'errorCode': 40000,
+        'httpStatus': 400,
+      },
+    ]);
+
+    await tester.tap(find.text('加载失败，点此重试'));
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -400));
+    await tester.pump();
+    expect(find.text('动态内容 p-2'), findsOneWidget);
+    expect(find.text('加载失败，点此重试'), findsNothing);
+  });
+
+  testWidgets('下拉刷新：整体替换列表；刷新失败保留旧列表 + SnackBar', (tester) async {
+    var attempts = 0;
+    repository.onFeed = (_, _) async {
+      attempts += 1;
+      if (attempts == 1) return feedPage([textCard('p-1')]);
+      if (attempts == 2) throw const ApiNetworkException();
+      return feedPage([textCard('p-9')]);
+    };
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+    expect(find.text('动态内容 p-1'), findsOneWidget);
+
+    // 第一次下拉：失败——旧列表保留、SnackBar 轻提示、事件上报。
+    await tester.fling(list(), const Offset(0, 400), 1000);
+    await tester.pumpAndSettle();
+    expect(find.text('动态内容 p-1'), findsOneWidget);
+    expect(find.text('网络异常，请检查网络后重试'), findsOneWidget);
+    expect(eventsNamed('feed_load_failed').single?['loadType'], 'refresh');
+
+    // 第二次下拉：成功——整体替换不残留旧卡。
+    await tester.fling(list(), const Offset(0, 400), 1000);
+    await tester.pumpAndSettle();
+    expect(find.text('动态内容 p-9'), findsOneWidget);
+    expect(find.text('动态内容 p-1'), findsNothing);
+  });
+
+  testWidgets('曝光结算 · 切走 Tab：可见 ≥500ms 的卡片计入，一段恰一条 feed_viewed', (
+    tester,
+  ) async {
+    repository.onFeed = (_, _) async =>
+        feedPage([textCard('p-1'), textCard('p-2')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -1000));
+    // 先渲染一帧（滚动后位置在帧末扫描），再驻留满 500ms（曝光判定），
+    // 随后切走 Tab 结算。
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 600));
+
+    expect(eventsNamed('feed_viewed'), isEmpty);
+    await pumpHome(tester, isActive: false);
+    await tester.pump();
+
+    final viewed = eventsNamed('feed_viewed');
+    expect(viewed, hasLength(1));
+    expect(viewed.single?['feedTab'], 'home');
+    expect(viewed.single?['impressionCount'], 2);
+    // 首屏自动预取不计刷新，本段无翻页。
+    expect(viewed.single?['refreshCount'], 0);
+    expect(viewed.single?['loadMoreCount'], 0);
+    // durationMs 取真实时钟（生产语义），widget 测试的 pump 只推进假
+    // 时钟，此处仅验证字段在场非负（精确口径见 feed_exposure_test）。
+    expect(viewed.single?['durationMs'], greaterThanOrEqualTo(0));
+
+    // 切回 Tab 开新段：再切走仍恰一条新事件（幂等不翻倍）。
+    await pumpHome(tester);
+    await tester.pump();
+    await pumpHome(tester, isActive: false);
+    await tester.pump();
+    expect(eventsNamed('feed_viewed'), hasLength(2));
+  });
+
+  testWidgets('曝光结算 · 快速滑过不计；刷新/翻页计数入段', (tester) async {
+    final cards = List.generate(6, (i) => textCard('p-$i'));
+    repository.onFeed = (_, cursor) async {
+      if (cursor == null) {
+        return feedPage(cards, nextCursor: 'c1', hasMore: true);
+      }
+      return feedPage([textCard('p-6')]);
+    };
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    // 快速滑到底（各卡驻留 <500ms）→ 触发一次翻页。
+    await tester.drag(list(), const Offset(0, -2000));
+    await tester.pumpAndSettle();
+    // 用户下拉刷新一次。
+    await tester.drag(list(), const Offset(0, 2000));
+    await tester.pump();
+    await tester.fling(list(), const Offset(0, 400), 1000);
+    await tester.pumpAndSettle();
+
+    await pumpHome(tester, isActive: false);
+    await tester.pump();
+
+    final viewed = eventsNamed('feed_viewed').single!;
+    expect(viewed['refreshCount'], 1);
+    expect(viewed['loadMoreCount'], 1);
+    // 快速滑过的中段卡片未驻留满 500ms，不应全量计曝光。
+    expect(viewed['impressionCount'], lessThan(cards.length));
+  });
+
+  testWidgets('曝光结算 · 退后台：结算一条，回前台开新段', (tester) async {
+    repository.onFeed = (_, _) async => feedPage([textCard('p-1')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.inactive);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.hidden);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.paused);
+    await tester.pump();
+    // 级联 inactive→hidden→paused 只结算一次。
+    expect(eventsNamed('feed_viewed'), hasLength(1));
+
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.hidden);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.inactive);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.resumed);
+    await tester.pump();
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.inactive);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.hidden);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.paused);
+    await tester.pump();
+    expect(eventsNamed('feed_viewed'), hasLength(2));
+
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.hidden);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.inactive);
+    tester.binding.handleAppLifecycleStateChanged(AppLifecycleState.resumed);
+    await tester.pump();
+  });
+
+  testWidgets('曝光结算 · 切到服务分段：结算；切回开新段', (tester) async {
+    repository.onFeed = (_, _) async => feedPage([textCard('p-1')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.text('本地服务'));
+    await tester.pump();
+    expect(eventsNamed('feed_viewed'), hasLength(1));
+
+    await tester.tap(find.text('社区动态'));
+    await tester.pump();
+    await tester.tap(find.text('本地服务'));
+    await tester.pump();
+    expect(eventsNamed('feed_viewed'), hasLength(2));
+  });
+
+  testWidgets('T3-14 取舍：整卡点按提示详情接入中（不导航 demo 详情）', (tester) async {
+    repository.onFeed = (_, _) async => feedPage([textCard('p-1')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+    await tester.drag(list(), const Offset(0, -600));
+    await tester.pump();
+
+    await tester.tap(find.text('动态内容 p-1'));
+    await tester.pump();
+    expect(find.text('帖子详情正在接入真实数据，敬请期待'), findsOneWidget);
+  });
+
+  testWidgets('搜索词过滤已加载卡片；无命中显搜索空态', (tester) async {
+    repository.onFeed = (_, _) async =>
+        feedPage([textCard('p-1'), textCard('p-2')]);
+
+    await pumpHome(tester);
+    await tester.pumpAndSettle();
+
+    await tester.enterText(find.byType(TextField), 'p-1');
+    await tester.pump();
+    expect(find.byType(PostCard), findsOneWidget);
+
+    await tester.enterText(find.byType(TextField), '不存在的词');
+    await tester.pump();
+    expect(find.byType(PostCard), findsNothing);
+    expect(find.text('没有找到相关动态'), findsOneWidget);
+  });
+}

test/widget_test.dart

@@ -4,6 +4,7 @@ import 'package:patbond_flutter/features/auth/session_manager.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import 'helpers/auth_test_helpers.dart';
+import 'helpers/community_test_helpers.dart';
 import 'helpers/pet_test_helpers.dart';
 
 void main() {
@@ -17,6 +18,8 @@ void main() {
         sessionManager: session,
         authRepository: FakeAuthRepository(),
         petsRepository: FakePetsRepository(),
+        communityRepository: FakeCommunityRepository()
+          ..onFeed = (_, _) async => feedPage(const []),
       ),
     );
     await tester.pumpAndSettle();