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>

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,
+    );
+  });
+}