新增：互动埋点与乐观更新视觉基建——字典 v3 互动八事件封装 + ToggleSync 成功上报与触点归因 + LikeButton 三层闪烁抑制动画（T3-16）

- community_interaction_analytics：post_liked/unliked、post_favorited/unfavorited、
  comment_create_succeeded/failed、user_followed/unfollowed 强类型封装（22 号
  白名单键集逐一对齐；textLengthBucket 分桶、httpStatus 由五位码推导、
  会话失效不上报）；comment_create_started 锁死 unknown 不封装
- CommunityController：toggleLike/toggleBookmark 增 source 触点归因
 （feed / post_detail），成功响应后经注入的 interactionAnalytics 上报
 （乐观翻转与失败不报）；adjustCommentCount 评论计数同源写入
 （详情副本与 Feed 卡片一并更新）
- LikeButton 升 Stateful：点按激活 240ms 弹性缩放 + 120ms 图标淡入、
  取消仅颜色渐出；回滚/对账零动画直接跳变、计数与状态成对更新、
  激活动画未播完等播完再跳（05 号 §3.5/§4）；减弱动态设置降级瞬变

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

lib/core/widgets/like_button.dart

@@ -31,12 +31,21 @@ enum LikeButtonVariant {
   final Color activeCountColor;
 }
 
-/// 点赞/收藏交互钮（05 号规范 §3.5 静态规格）：图标 20 + 计数 13/w600，
-/// 未激活一律 `inkSoft`（6.59:1）。触控 44×44 由 padding 撑足。
+/// 点赞/收藏交互钮（05 号规范 §3.5）：图标 20 + 计数 13/w600，未激活
+/// 一律 `inkSoft`（6.59:1）。触控 44×44 由 padding 撑足。
 ///
-/// T3-14 只做展示（[onPressed] 传 null 即禁用态，仍按正常色渲染计数与
-/// 状态）；乐观更新动画与 ToggleSync 接线属 T3-15/16。
-class LikeButton extends StatelessWidget {
+/// 乐观更新视觉（§3.5/§4 三层闪烁抑制的 UI 半边，状态本体由持有方经
+/// ToggleSync 驱动）：
+///
+/// - **点按驱动**的状态变化：激活播 240ms 弹性缩放（1→1.25→1）+ 图标
+///   120ms 淡入；取消仅 120ms 颜色渐出、无缩放。
+/// - **非点按驱动**的状态变化（失败回滚 / 服务端对账）：零动画直接跳变；
+///   若激活动画未播完，等播完再跳（避免动画中途反转的抖动，§4.3a）。
+/// - 计数变化一律直接替换，不做滚动动画（回滚时无二次滚动）。
+/// - 系统「减弱动态效果」开启时全部降级为瞬变。
+///
+/// [onPressed] 传 null 即纯展示禁用态（仍按正常色渲染计数与状态）。
+class LikeButton extends StatefulWidget {
   const LikeButton({
     required this.variant,
     required this.active,
@@ -52,15 +61,106 @@ class LikeButton extends StatelessWidget {
   final VoidCallback? onPressed;
   final String? semanticLabel;
 
+  @override
+  State<LikeButton> createState() => _LikeButtonState();
+}
+
+class _LikeButtonState extends State<LikeButton>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _scaleController = AnimationController(
+    vsync: this,
+    duration: const Duration(milliseconds: 240),
+  );
+  late final Animation<double> _scale = TweenSequence<double>([
+    TweenSequenceItem(
+      tween: Tween<double>(
+        begin: 1,
+        end: 1.25,
+      ).chain(CurveTween(curve: Curves.easeOut)),
+      weight: 40,
+    ),
+    TweenSequenceItem(
+      tween: Tween<double>(
+        begin: 1.25,
+        end: 1,
+      ).chain(CurveTween(curve: Curves.easeOutBack)),
+      weight: 60,
+    ),
+  ]).animate(_scaleController);
+
+  /// 当前展示态（回滚等待动画播完期间可短暂落后于 widget.active）。
+  late bool _displayActive = widget.active;
+
+  /// 展示计数与状态成对更新（§4.3c：回滚不出现「心已灭计数未减」中间帧）。
+  late int _displayCount = widget.count;
+
+  /// 最近一次点按的期望目标态；didUpdateWidget 以此区分「点按驱动」
+  /// （播动画）与「回滚/对账」（零动画跳变）。
+  bool? _expectedTarget;
+
+  /// 图标切换是否走 120ms 淡入淡出（点按驱动）；回滚跳变置 false。
+  bool _fadeSwap = false;
+
+  bool get _reduceMotion =>
+      MediaQuery.maybeOf(context)?.disableAnimations ?? false;
+
+  @override
+  void didUpdateWidget(LikeButton oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.active == widget.active) {
+      // 状态未变的计数变化 = 服务端对账：静默替换、不播动画（§4.4）。
+      _displayCount = widget.count;
+      return;
+    }
+    final tapDriven = _expectedTarget == widget.active;
+    _expectedTarget = null;
+    if (tapDriven && !_reduceMotion) {
+      _fadeSwap = true;
+      _displayActive = widget.active;
+      _displayCount = widget.count;
+      if (widget.active) _scaleController.forward(from: 0);
+      return;
+    }
+    // 回滚 / 对账：零动画、计数与状态成对跳变。激活动画未播完则等
+    // 播完再跳（§4.3a，避免动画中途反转的抖动）。
+    _fadeSwap = false;
+    if (_scaleController.isAnimating) {
+      _scaleController.forward().whenComplete(() {
+        if (mounted) {
+          setState(() {
+            _displayActive = widget.active;
+            _displayCount = widget.count;
+          });
+        }
+      });
+    } else {
+      _displayActive = widget.active;
+      _displayCount = widget.count;
+    }
+  }
+
+  void _handleTap() {
+    _expectedTarget = !widget.active;
+    widget.onPressed!();
+  }
+
+  @override
+  void dispose() {
+    _scaleController.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
+    final variant = widget.variant;
+    final active = _displayActive;
     final iconColor = active ? variant.activeIconColor : AppColors.inkSoft;
     final countColor = active ? variant.activeCountColor : AppColors.inkSoft;
     return Semantics(
-      label: semanticLabel,
-      button: onPressed != null,
+      label: widget.semanticLabel,
+      button: widget.onPressed != null,
       child: InkWell(
-        onTap: onPressed,
+        onTap: widget.onPressed == null ? null : _handleTap,
         borderRadius: BorderRadius.circular(AppRadius.pill),
         child: ConstrainedBox(
           constraints: const BoxConstraints(minWidth: 44, minHeight: 44),
@@ -69,14 +169,24 @@ class LikeButton extends StatelessWidget {
             child: Row(
               mainAxisSize: MainAxisSize.min,
               children: [
-                Icon(
+                ScaleTransition(
+                  scale: _scale,
+                  child: AnimatedSwitcher(
+                    duration: _fadeSwap
+                        ? const Duration(milliseconds: 120)
+                        : Duration.zero,
+                    child: Icon(
                       active ? variant.activeIcon : variant.inactiveIcon,
+                      key: ValueKey(active),
                       size: 20,
                       color: iconColor,
                     ),
+                  ),
+                ),
                 const SizedBox(width: 4),
+                // 计数直接替换（§3.5：不做滚动动画，避免回滚二次滚动）。
                 Text(
-                  '$count',
+                  '$_displayCount',
                   style: TextStyle(
                     color: countColor,
                     fontSize: 13,

lib/features/community/community_controller.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/foundation.dart';
 import 'package:patbond_flutter/core/network/api_exception.dart';
+import 'package:patbond_flutter/features/community/community_interaction_analytics.dart';
 import 'package:patbond_flutter/features/community/community_models.dart';
 import 'package:patbond_flutter/features/community/community_repository.dart';
 import 'package:patbond_flutter/features/community/toggle_sync.dart';
@@ -18,7 +19,7 @@ enum LoadMorePhase { idle, loading, error }
 /// 评论列表只属详情页，按「页面级状态按页自建」纪律经 [repository]
 /// 自取，不膨胀本控制器。服务端是唯一事实来源，内存副本仅作展示缓存。
 class CommunityController extends ChangeNotifier {
-  CommunityController({required this._repository}) {
+  CommunityController({required this._repository, this._interactionAnalytics}) {
     _likeSync = ToggleSync(
       read: (id) {
         final post = _postCache[id];
@@ -35,6 +36,11 @@ class CommunityController extends ChangeNotifier {
         final state = target
             ? await _repository.likePost(id)
             : await _repository.unlikePost(id);
+        // 成功响应后上报（06 §1.4 口径；乐观翻转与失败均不报）。
+        final source = _likeSources[id] ?? InteractionSource.feed;
+        target
+            ? _interactionAnalytics?.postLiked(source: source)
+            : _interactionAnalytics?.postUnliked(source: source);
         return ToggleOutcome(active: state.liked, count: state.likeCount);
       },
       generation: () => _generation,
@@ -62,6 +68,10 @@ class CommunityController extends ChangeNotifier {
         final state = target
             ? await _repository.bookmarkPost(id)
             : await _repository.unbookmarkPost(id);
+        final source = _bookmarkSources[id] ?? InteractionSource.feed;
+        target
+            ? _interactionAnalytics?.postFavorited(source: source)
+            : _interactionAnalytics?.postUnfavorited(source: source);
         return ToggleOutcome(
           active: state.bookmarked,
           count: state.bookmarkCount,
@@ -73,6 +83,12 @@ class CommunityController extends ChangeNotifier {
   }
 
   final CommunityRepository _repository;
+  final CommunityInteractionAnalytics? _interactionAnalytics;
+
+  /// 各帖最近一次 toggle 的触点来源（Feed 卡片 / 详情页共享同一实例，
+  /// 成功响应上报时按发起触点归因）。
+  final Map<String, InteractionSource> _likeSources = {};
+  final Map<String, InteractionSource> _bookmarkSources = {};
 
   /// 页面级状态（评论列表、我的帖子、收藏页等）按页直接经仓库取数。
   CommunityRepository get repository => _repository;
@@ -193,10 +209,34 @@ class CommunityController extends ChangeNotifier {
   }
 
   /// 点赞/取消点赞（乐观翻转，终态由 [ToggleSync] 对账收敛，不外抛）。
-  void toggleLike(String postId) => _likeSync.toggle(postId);
+  /// [source] 为触点来源（埋点归因），Feed 卡片缺省 feed、详情页传
+  /// post_detail。
+  void toggleLike(
+    String postId, {
+    InteractionSource source = InteractionSource.feed,
+  }) {
+    _likeSources[postId] = source;
+    _likeSync.toggle(postId);
+  }
 
   /// 收藏/取消收藏（与点赞同构）。
-  void toggleBookmark(String postId) => _bookmarkSync.toggle(postId);
+  void toggleBookmark(
+    String postId, {
+    InteractionSource source = InteractionSource.feed,
+  }) {
+    _bookmarkSources[postId] = source;
+    _bookmarkSync.toggle(postId);
+  }
+
+  /// 评论创建/删除后的计数调整（详情页与 Feed 卡片同源写入，
+  /// 服务端 comment_count 由写侧同事务维护，本地只做展示对齐）。
+  void adjustCommentCount(String postId, int delta) {
+    final current =
+        _postCache[postId]?.commentCount ?? _cardOrNull(postId)?.commentCount;
+    if (current == null) return;
+    final next = current + delta;
+    _writeInteraction(postId, commentCount: next < 0 ? 0 : next);
+  }
 
   /// 消费一次性 toggle 错误（SnackBar 展示后清除）。
   void clearToggleError() => _toggleError = null;
@@ -215,6 +255,8 @@ class CommunityController extends ChangeNotifier {
     _loadMoreError = null;
     _toggleError = null;
     _postCache.clear();
+    _likeSources.clear();
+    _bookmarkSources.clear();
     _likeSync.reset();
     _bookmarkSync.reset();
     _notify();
@@ -234,6 +276,7 @@ class CommunityController extends ChangeNotifier {
     int? likeCount,
     bool? bookmarkedByMe,
     int? bookmarkCount,
+    int? commentCount,
   }) {
     final post = _postCache[postId];
     if (post != null) {
@@ -242,6 +285,7 @@ class CommunityController extends ChangeNotifier {
         likeCount: likeCount,
         bookmarkedByMe: bookmarkedByMe,
         bookmarkCount: bookmarkCount,
+        commentCount: commentCount,
       );
     }
     final index = _feed.indexWhere((card) => card.id == postId);
@@ -252,6 +296,7 @@ class CommunityController extends ChangeNotifier {
           likeCount: likeCount,
           bookmarkedByMe: bookmarkedByMe,
           bookmarkCount: bookmarkCount,
+          commentCount: commentCount,
         );
     }
     if (post != null || index != -1) _notify();

lib/features/community/community_interaction_analytics.dart

@@ -0,0 +1,137 @@
+import 'package:patbond_flutter/analytics/page_view_tracker.dart';
+import 'package:patbond_flutter/core/network/api_exception.dart';
+
+/// 互动域埋点强类型封装（06 号规划 §1.4 字典 v3 互动八事件；后端白名单
+/// 已随 api dev@8089c06 就绪，22 号报告 §1）。沿 pet/feed 域惯例：枚举
+/// 编译期锁死，业务代码禁止手拼事件名与属性；只记行为不记内容
+/// （隐私红线：postId/commentId 等内容 ID 一律不进 props）。
+///
+/// 点赞/收藏/关注**不埋失败**（06 §1.4 取舍：幂等写入单点交互，失败率
+/// 靠服务端错误率观测）；`comment_create_started` 被字典锁死 unknown，
+/// 不得上报（22 号 §1 末段）。
+
+/// 互动触点来源（06 §1.4 source 枚举）。M3 接 feed / post_detail；
+/// user_profile / follow_list 随后续页面启用。
+enum InteractionSource {
+  feed('feed'),
+  postDetail('post_detail'),
+  userProfile('user_profile'),
+  followList('follow_list');
+
+  const InteractionSource(this.value);
+
+  final String value;
+}
+
+/// 评论创建失败原因（06 §1.4 失败枚举基底）。网络归并口径同 pet/feed 域：
+/// 断网/超时/5xx 均并入 network_error，server_error 保留兜底。
+enum CommentCreateFailureReason {
+  validationError('validation_error'),
+  notFound('not_found'),
+  rateLimited('rate_limited'),
+  networkError('network_error'),
+  serverError('server_error');
+
+  const CommentCreateFailureReason(this.value);
+
+  final String value;
+}
+
+/// 类型化异常 → 评论失败原因；会话失效返回 null（应用即将回登录页，
+/// 不作为评论失败上报，feed 域同款口径）。
+CommentCreateFailureReason? commentCreateFailureReasonOf(ApiException error) =>
+    switch (error) {
+      ApiNetworkException _ => CommentCreateFailureReason.networkError,
+      ApiRateLimitException _ => CommentCreateFailureReason.rateLimited,
+      SessionExpiredException _ => null,
+      ApiBusinessException(:final code) => switch (code) {
+        ApiCodes.paramError => CommentCreateFailureReason.validationError,
+        ApiCodes.postNotFound ||
+        ApiCodes.commentNotFound ||
+        ApiCodes.communityUserNotFound => CommentCreateFailureReason.notFound,
+        _ => CommentCreateFailureReason.serverError,
+      },
+    };
+
+/// 正文规模分桶（06 §1.3 隐私红线 1：不报精确字数）。
+/// empty / short(≤50) / medium(51–500) / long(>500)。
+String textLengthBucketOf(int length) {
+  if (length <= 0) return 'empty';
+  if (length <= 50) return 'short';
+  if (length <= 500) return 'medium';
+  return 'long';
+}
+
+class CommunityInteractionAnalytics {
+  CommunityInteractionAnalytics(this._track);
+
+  /// 生产传 `AnalyticsService.trackEvent`，测试传录制桩。
+  final TrackEventFn _track;
+
+  /// 点赞成功响应后（乐观翻转本身不报；单飞合并链每个实际抵达服务端
+  /// 并成功的状态变更各报一条，与「成功响应后」的字典口径一致）。
+  void postLiked({required InteractionSource source}) {
+    _track('post_liked', {'source': source.value});
+  }
+
+  /// 取消点赞成功响应后。
+  void postUnliked({required InteractionSource source}) {
+    _track('post_unliked', {'source': source.value});
+  }
+
+  /// 收藏成功响应后。
+  void postFavorited({required InteractionSource source}) {
+    _track('post_favorited', {'source': source.value});
+  }
+
+  /// 取消收藏成功响应后。
+  void postUnfavorited({required InteractionSource source}) {
+    _track('post_unfavorited', {'source': source.value});
+  }
+
+  /// 评论提交成功响应后。
+  ///
+  /// [durationMs]：本次输入会话（首个字符输入）→ 成功响应的耗时
+  /// （评论不设 started 事件，时长随成功事件带出）；
+  /// [textLength] 经 [textLengthBucketOf] 分桶后上报，精确字数不出端。
+  void commentCreateSucceeded({
+    required int durationMs,
+    required bool isReply,
+    required int textLength,
+  }) {
+    _track('comment_create_succeeded', {
+      'durationMs': durationMs,
+      'isReply': isReply,
+      'textLengthBucket': textLengthBucketOf(textLength),
+    });
+  }
+
+  /// 评论提交失败。
+  ///
+  /// [errorCode] 为业务错误码（网络错误时缺席）；[httpStatus] 由五位
+  /// 业务码推导（`code ~/ 100`，pet 域同款口径）；[attemptSeq] 为本次
+  /// 输入会话内第几次提交尝试（从 1 起，成功或清空输入后重置）。
+  void commentCreateFailed({
+    required CommentCreateFailureReason reason,
+    required int attemptSeq,
+    int? errorCode,
+  }) {
+    _track('comment_create_failed', {
+      'failureReason': reason.value,
+      'attemptSeq': attemptSeq,
+      'errorCode': ?errorCode,
+      if (errorCode != null && errorCode >= 10000)
+        'httpStatus': errorCode ~/ 100,
+    });
+  }
+
+  /// 关注成功响应后。
+  void userFollowed({required InteractionSource source}) {
+    _track('user_followed', {'source': source.value});
+  }
+
+  /// 取关成功响应后。
+  void userUnfollowed({required InteractionSource source}) {
+    _track('user_unfollowed', {'source': source.value});
+  }
+}

test/core/widgets/like_button_test.dart

@@ -0,0 +1,155 @@
+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';
+
+/// 宿主：模拟持有方（controller）的状态翻转——点按经 [onTap] 乐观翻转，
+/// 外部（回滚/对账）经 [setActive] 直接改。
+class _Host extends StatefulWidget {
+  const _Host({required this.initialActive, required this.initialCount});
+
+  final bool initialActive;
+  final int initialCount;
+
+  @override
+  State<_Host> createState() => _HostState();
+}
+
+class _HostState extends State<_Host> {
+  late bool active = widget.initialActive;
+  late int count = widget.initialCount;
+
+  void setExternal({required bool active, required int count}) {
+    setState(() {
+      this.active = active;
+      this.count = count;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      theme: buildAppTheme(),
+      home: Scaffold(
+        body: Center(
+          child: LikeButton(
+            variant: LikeButtonVariant.like,
+            active: active,
+            count: count,
+            onPressed: () => setState(() {
+              active = !active;
+              count += active ? 1 : -1;
+            }),
+            semanticLabel: '点赞',
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+void main() {
+  double scaleOf(WidgetTester tester) => tester
+      .widget<ScaleTransition>(
+        find.descendant(
+          of: find.byType(LikeButton),
+          matching: find.byType(ScaleTransition),
+        ),
+      )
+      .scale
+      .value;
+
+  testWidgets('点按激活：240ms 弹性缩放动画（中途 >1，播完归位）', (tester) async {
+    await tester.pumpWidget(const _Host(initialActive: false, initialCount: 6));
+
+    await tester.tap(find.byIcon(Icons.favorite_border));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 90));
+    expect(scaleOf(tester), greaterThan(1.0));
+    expect(find.byIcon(Icons.favorite), findsOneWidget);
+    expect(find.text('7'), findsOneWidget);
+
+    await tester.pumpAndSettle();
+    expect(scaleOf(tester), 1.0);
+  });
+
+  testWidgets('点按取消：仅颜色切换，无缩放动画', (tester) async {
+    await tester.pumpWidget(const _Host(initialActive: true, initialCount: 7));
+
+    await tester.tap(find.byIcon(Icons.favorite));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 90));
+    expect(scaleOf(tester), 1.0);
+    expect(find.byIcon(Icons.favorite_border), findsOneWidget);
+    expect(find.text('6'), findsOneWidget);
+    await tester.pumpAndSettle();
+  });
+
+  testWidgets('外部回滚：零动画直接跳变，计数与状态成对恢复', (tester) async {
+    await tester.pumpWidget(const _Host(initialActive: false, initialCount: 6));
+
+    // 点按激活并播完动画（在途请求随后失败的场景）。
+    await tester.tap(find.byIcon(Icons.favorite_border));
+    await tester.pumpAndSettle();
+    expect(find.byIcon(Icons.favorite), findsOneWidget);
+
+    // 外部（非点按）回滚：下一帧即恢复，无过渡动画。
+    tester
+        .state<_HostState>(find.byType(_Host))
+        .setExternal(active: false, count: 6);
+    await tester.pump();
+    expect(find.byIcon(Icons.favorite_border), findsOneWidget);
+    expect(find.text('6'), findsOneWidget);
+    expect(scaleOf(tester), 1.0);
+  });
+
+  testWidgets('激活动画未播完时回滚：等播完再成对跳变（§4.3a 抖动抑制）', (tester) async {
+    await tester.pumpWidget(const _Host(initialActive: false, initialCount: 6));
+
+    await tester.tap(find.byIcon(Icons.favorite_border));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 60));
+    expect(find.byIcon(Icons.favorite), findsOneWidget);
+
+    // 动画中途回滚：本帧仍显示激活视觉（等待播完），计数同持。
+    tester
+        .state<_HostState>(find.byType(_Host))
+        .setExternal(active: false, count: 6);
+    await tester.pump();
+    expect(find.byIcon(Icons.favorite), findsOneWidget);
+    expect(find.text('7'), findsOneWidget);
+
+    // 播完后成对跳回。
+    await tester.pumpAndSettle();
+    expect(find.byIcon(Icons.favorite_border), findsOneWidget);
+    expect(find.text('6'), findsOneWidget);
+  });
+
+  testWidgets('对账静默：状态不变的计数变化直接替换，无动画', (tester) async {
+    await tester.pumpWidget(const _Host(initialActive: true, initialCount: 7));
+
+    tester
+        .state<_HostState>(find.byType(_Host))
+        .setExternal(active: true, count: 9);
+    await tester.pump();
+    expect(find.text('9'), findsOneWidget);
+    expect(scaleOf(tester), 1.0);
+  });
+
+  testWidgets('onPressed 为 null 时禁用但照常渲染激活态', (tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: buildAppTheme(),
+        home: const Scaffold(
+          body: LikeButton(
+            variant: LikeButtonVariant.bookmark,
+            active: true,
+            count: 2,
+          ),
+        ),
+      ),
+    );
+    expect(find.byIcon(Icons.bookmark), findsOneWidget);
+    expect(find.text('2'), findsOneWidget);
+  });
+}

test/features/community/community_interaction_analytics_test.dart

@@ -0,0 +1,126 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:patbond_flutter/core/network/api_exception.dart';
+import 'package:patbond_flutter/features/community/community_interaction_analytics.dart';
+
+void main() {
+  late List<(String, Map<String, dynamic>?)> events;
+  late CommunityInteractionAnalytics analytics;
+
+  setUp(() {
+    events = [];
+    analytics = CommunityInteractionAnalytics(
+      (name, [props]) async => events.add((name, props)),
+    );
+  });
+
+  List<String> names() => events.map((e) => e.$1).toList();
+  List<Map<String, dynamic>?> props() => events.map((e) => e.$2).toList();
+
+  test('互动四事件：source 逐字段（22 号白名单键集）', () {
+    analytics.postLiked(source: InteractionSource.feed);
+    analytics.postUnliked(source: InteractionSource.postDetail);
+    analytics.postFavorited(source: InteractionSource.postDetail);
+    analytics.postUnfavorited(source: InteractionSource.feed);
+
+    expect(names(), [
+      'post_liked',
+      'post_unliked',
+      'post_favorited',
+      'post_unfavorited',
+    ]);
+    expect(props(), [
+      {'source': 'feed'},
+      {'source': 'post_detail'},
+      {'source': 'post_detail'},
+      {'source': 'feed'},
+    ]);
+  });
+
+  test('comment_create_succeeded：durationMs/isReply/textLengthBucket', () {
+    analytics.commentCreateSucceeded(
+      durationMs: 4200,
+      isReply: false,
+      textLength: 12,
+    );
+    expect(names(), ['comment_create_succeeded']);
+    expect(props().single, {
+      'durationMs': 4200,
+      'isReply': false,
+      'textLengthBucket': 'short',
+    });
+  });
+
+  test('comment_create_failed：httpStatus 由五位业务码推导，网络错误缺席', () {
+    analytics.commentCreateFailed(
+      reason: CommentCreateFailureReason.validationError,
+      attemptSeq: 2,
+      errorCode: 40000,
+    );
+    analytics.commentCreateFailed(
+      reason: CommentCreateFailureReason.networkError,
+      attemptSeq: 3,
+    );
+    expect(names(), ['comment_create_failed', 'comment_create_failed']);
+    expect(props(), [
+      {
+        'failureReason': 'validation_error',
+        'attemptSeq': 2,
+        'errorCode': 40000,
+        'httpStatus': 400,
+      },
+      {'failureReason': 'network_error', 'attemptSeq': 3},
+    ]);
+  });
+
+  test('关注对：user_followed / user_unfollowed', () {
+    analytics.userFollowed(source: InteractionSource.postDetail);
+    analytics.userUnfollowed(source: InteractionSource.postDetail);
+    expect(names(), ['user_followed', 'user_unfollowed']);
+    expect(props(), [
+      {'source': 'post_detail'},
+      {'source': 'post_detail'},
+    ]);
+  });
+
+  test('textLengthBucketOf 分桶边界（06 §1.3 红线：不报精确字数）', () {
+    expect(textLengthBucketOf(0), 'empty');
+    expect(textLengthBucketOf(1), 'short');
+    expect(textLengthBucketOf(50), 'short');
+    expect(textLengthBucketOf(51), 'medium');
+    expect(textLengthBucketOf(500), 'medium');
+    expect(textLengthBucketOf(501), 'long');
+  });
+
+  test('失败原因映射：网络归并口径 + 防枚举族归 not_found + 会话失效 null', () {
+    expect(
+      commentCreateFailureReasonOf(const ApiNetworkException()),
+      CommentCreateFailureReason.networkError,
+    );
+    expect(
+      commentCreateFailureReasonOf(const ApiRateLimitException()),
+      CommentCreateFailureReason.rateLimited,
+    );
+    expect(
+      commentCreateFailureReasonOf(
+        const ApiBusinessException(code: ApiCodes.paramError, message: 'x'),
+      ),
+      CommentCreateFailureReason.validationError,
+    );
+    expect(
+      commentCreateFailureReasonOf(
+        const ApiBusinessException(code: ApiCodes.postNotFound, message: 'x'),
+      ),
+      CommentCreateFailureReason.notFound,
+    );
+    expect(
+      commentCreateFailureReasonOf(
+        const ApiBusinessException(code: 50000, message: 'x'),
+      ),
+      CommentCreateFailureReason.serverError,
+    );
+    expect(
+      commentCreateFailureReasonOf(const SessionExpiredException()),
+      isNull,
+    );
+  });
+}