diff --git a/client/lib/modules/dual_check/api.dart b/client/lib/modules/dual_check/api.dart
index 2795ce5..2dcf02c 100644
--- a/client/lib/modules/dual_check/api.dart
+++ b/client/lib/modules/dual_check/api.dart
@@ -1,50 +1,40 @@
 // DualCheck API 封装
-// 后端统一响应格式：{code:0, message, data}
-// WebSocket 消息格式：{type, data, error}
+import 'dart:convert';
+import 'package:flutter/foundation.dart' show kIsWeb;
+
 import 'package:dio/dio.dart';
-import 'package:flutter/foundation.dart';
 
-/// 后端地址
-const String _baseUrl = kIsWeb
-    ? 'http://localhost:8080'
-    : 'http://127.0.0.1:8080';
-
-/// WebSocket 地址
+// ── URL ──
+const String _baseUrl =
+    kIsWeb ? 'http://localhost:8080' : 'http://127.0.0.1:8080';
 const String _wsBaseUrl =
     kIsWeb ? 'ws://localhost:8080' : 'ws://127.0.0.1:8080';
 
 class DualCheckApi {
-  DualCheckApi()
-      : _dio = Dio(BaseOptions(
-          baseUrl: _baseUrl,
-          connectTimeout: const Duration(seconds: 10),
-          receiveTimeout: const Duration(seconds: 10),
-        )) {
-    _dio.interceptors.add(InterceptorsWrapper(
-      onResponse: (response, handler) {
-        final data = response.data;
-        if (data is Map<String, dynamic> && data['code'] != 0) {
-          handler.reject(DioException(
-            requestOptions: response.requestOptions,
-            response: response,
-            type: DioExceptionType.badResponse,
-            error: _BizError(data['code'] as int, data['message'] as String),
-          ));
-          return;
-        }
-        handler.next(response);
-      },
-    ));
-  }
+  DualCheckApi._();
+  static final DualCheckApi instance = DualCheckApi._();
 
-  final Dio _dio;
+  final Dio _dio = Dio(BaseOptions(
+    baseUrl: _baseUrl,
+    contentType: 'application/json',
+    connectTimeout: const Duration(seconds: 5),
+    receiveTimeout: const Duration(seconds: 10),
+    sendTimeout: const Duration(seconds: 10),
+  ))
+    ..interceptors.add(_BizErrorInterceptor());
 
   // ── Create ──
 
-  Future<CreateResp> createSession({required String nickname}) async {
+  Future<CreateResp> createSession({
+    required String nickname,
+    required String browserId,
+  }) async {
     final res = await _dio.post<Map<String, dynamic>>(
       '/api/v1/dual-check/create',
-      data: {'nickname': nickname},
+      data: {
+        'nickname': nickname,
+        'browser_id': browserId,
+      },
     );
     final d = res.data!['data'] as Map<String, dynamic>;
     return CreateResp(
@@ -82,8 +72,9 @@ class DualCheckApi {
   // ── CheckSession ──
 
   Future<CheckResp> checkSession(String sessionId) async {
-    final res = await _dio.get<Map<String, dynamic>>(
-      '/api/v1/dual-check/check/$sessionId',
+    final res = await _dio.post<Map<String, dynamic>>(
+      '/api/v1/dual-check/check',
+      data: {'session_id': sessionId},
     );
     final d = res.data!['data'] as Map<String, dynamic>;
     return CheckResp(
@@ -97,18 +88,42 @@ class DualCheckApi {
   // ── GetSession 全量快照 ──
 
   Future<SessionResp> getSession(String sessionId) async {
-    final res = await _dio.get<Map<String, dynamic>>(
-      '/api/v1/dual-check/session/$sessionId',
+    final res = await _dio.post<Map<String, dynamic>>(
+      '/api/v1/dual-check/session',
+      data: {'session_id': sessionId},
     );
     return parseSession(res.data!['data'] as Map<String, dynamic>);
   }
 
+  // ── Join 参与者加入登记 ──
+
+  Future<Map<String, dynamic>> joinParticipant({
+    required String sessionId,
+    required String nickname,
+  }) async {
+    final res = await _dio.post<Map<String, dynamic>>(
+      '/api/v1/dual-check/join',
+      data: {'session_id': sessionId, 'nickname': nickname},
+    );
+    return res.data!['data'] as Map<String, dynamic>;
+  }
+
   // ── SetResubmit 发起方切换"允许参与者重新提交" ──
 
   Future<SessionResp> setResubmit(String sessionId, {required bool allow}) async {
     final res = await _dio.post<Map<String, dynamic>>(
-      '/api/v1/dual-check/session/$sessionId/resubmit',
-      data: {'allow': allow},
+      '/api/v1/dual-check/resubmit',
+      data: {'session_id': sessionId, 'allow': allow},
+    );
+    return parseSession(res.data!['data'] as Map<String, dynamic>);
+  }
+
+  // ── SetIgnoreWs 发起方切换"忽略首尾空白" ──
+
+  Future<SessionResp> setIgnoreWs(String sessionId, {required bool ignore}) async {
+    final res = await _dio.post<Map<String, dynamic>>(
+      '/api/v1/dual-check/ignore-ws',
+      data: {'session_id': sessionId, 'ignore': ignore},
     );
     return parseSession(res.data!['data'] as Map<String, dynamic>);
   }
@@ -116,7 +131,7 @@ class DualCheckApi {
   // ── EndSession 发起方主动结束会话 ──
 
   Future<void> endSession(String sessionId) async {
-    await _dio.post('/api/v1/dual-check/session/$sessionId/end');
+    await _dio.post('/api/v1/dual-check/end', data: {'session_id': sessionId});
   }
 
   static SessionResp parseSession(Map<String, dynamic> d) {
@@ -128,6 +143,7 @@ class DualCheckApi {
       initiatorNickname: (d['initiator_nickname'] ?? '') as String,
       initiatorReady: d['initiator_ready'] as bool,
       allowResubmit: (d['allow_resubmit'] as bool?) ?? false,
+      ignoreWs: (d['ignore_ws'] as bool?) ?? false,
       participants: parts,
       ttlSeconds: d['ttl_seconds'] as int,
     );
@@ -139,14 +155,57 @@ class DualCheckApi {
     required String sessionId,
     required String role,
     required String nickname,
+    required String browserId,
   }) {
     return '$_wsBaseUrl/api/v1/dual-check/ws'
         '?session_id=${Uri.encodeQueryComponent(sessionId)}'
         '&role=$role'
-        '&nickname=${Uri.encodeQueryComponent(nickname)}';
+        '&nickname=${Uri.encodeQueryComponent(nickname)}'
+        '&browser_id=${Uri.encodeQueryComponent(browserId)}';
   }
 }
 
+// ── Dio 拦截器：把后端业务错误转成 DioException ──
+
+class _BizErrorInterceptor extends Interceptor {
+  @override
+  void onResponse(Response response, ResponseInterceptorHandler handler) {
+    final data = response.data;
+    if (data is Map<String, dynamic>) {
+      final code = data['code'];
+      if (code != null && code != 0) {
+        final msg = data['message']?.toString() ?? '请求失败';
+        handler.reject(DioException(
+          requestOptions: response.requestOptions,
+          response: response,
+          error: _BizError(code as int, msg),
+          type: DioExceptionType.badResponse,
+        ));
+        return;
+      }
+    }
+    handler.next(response);
+  }
+}
+
+class _BizError {
+  final int code;
+  final String message;
+  const _BizError(this.code, this.message);
+  @override
+  String toString() => 'BusinessError($code): $message';
+}
+
+bool isBizError(DioException e) => e.error is _BizError;
+int? bizErrorCode(DioException e) {
+  final err = e.error;
+  return err is _BizError ? err.code : null;
+}
+String bizErrorMessage(DioException e) {
+  final err = e.error;
+  return err is _BizError ? err.message : (e.message ?? '请求失败');
+}
+
 // ── 数据模型 ──
 
 class CreateResp {
@@ -187,14 +246,12 @@ class ParticipantResp {
     required this.submitted,
     this.match,
   });
-  factory ParticipantResp.fromMap(Map<String, dynamic> m) {
-    return ParticipantResp(
-      nickname: m['nickname'] as String,
-      joined: m['joined'] as bool? ?? true,
-      submitted: m['submitted'] as bool,
-      match: m['match'] as bool?,
-    );
-  }
+  factory ParticipantResp.fromMap(Map<String, dynamic> m) => ParticipantResp(
+        nickname: m['nickname'] as String,
+        joined: (m['joined'] as bool?) ?? true,
+        submitted: (m['submitted'] as bool?) ?? false,
+        match: m['match'] as bool?,
+      );
 }
 
 class SessionResp {
@@ -202,6 +259,7 @@ class SessionResp {
   final String initiatorNickname;
   final bool initiatorReady;
   final bool allowResubmit;
+  final bool ignoreWs;
   final List<ParticipantResp> participants;
   final int ttlSeconds;
   SessionResp({
@@ -209,45 +267,49 @@ class SessionResp {
     required this.initiatorNickname,
     required this.initiatorReady,
     required this.allowResubmit,
+    required this.ignoreWs,
     required this.participants,
     required this.ttlSeconds,
   });
+
+  SessionResp copyWith({
+    String? sessionId,
+    String? initiatorNickname,
+    bool? initiatorReady,
+    bool? allowResubmit,
+    bool? ignoreWs,
+    List<ParticipantResp>? participants,
+    int? ttlSeconds,
+  }) =>
+      SessionResp(
+        sessionId: sessionId ?? this.sessionId,
+        initiatorNickname: initiatorNickname ?? this.initiatorNickname,
+        initiatorReady: initiatorReady ?? this.initiatorReady,
+        allowResubmit: allowResubmit ?? this.allowResubmit,
+        ignoreWs: ignoreWs ?? this.ignoreWs,
+        participants: participants ?? this.participants,
+        ttlSeconds: ttlSeconds ?? this.ttlSeconds,
+      );
 }
 
-// ── WS 消息类型 ──
+// ── WS 消息解析 ──
 
 class WSMessage {
   final String type;
   final Map<String, dynamic> data;
-  final String? error;
+  final String error;
+  WSMessage({required this.type, required this.data, this.error = ''});
 
-  WSMessage({required this.type, required this.data, this.error});
-
-  factory WSMessage.fromJson(Map<String, dynamic> json) {
-    return WSMessage(
-      type: json['type'] as String,
-      data: (json['data'] as Map<String, dynamic>?) ?? const {},
-      error: json['error'] as String?,
-    );
+  factory WSMessage.fromJson(String raw) {
+    try {
+      final m = jsonDecode(raw) as Map<String, dynamic>;
+      return WSMessage(
+        type: m['type'] as String? ?? '',
+        data: (m['data'] as Map<String, dynamic>?) ?? {},
+        error: (m['error'] as String?) ?? '',
+      );
+    } catch (_) {
+      return WSMessage(type: '', data: {});
+    }
   }
 }
-
-// ── 业务错误处理 ──
-
-class _BizError implements Exception {
-  _BizError(this.code, this.message);
-  final int code;
-  final String message;
-  @override
-  String toString() => '[biz:$code] $message';
-}
-
-bool isBizError(DioException e) => e.error is _BizError;
-int? bizErrorCode(DioException e) {
-  final err = e.error;
-  return err is _BizError ? err.code : null;
-}
-String bizErrorMessage(DioException e) {
-  final err = e.error;
-  return err is _BizError ? err.message : (e.message ?? '请求失败');
-}
diff --git a/client/lib/modules/dual_check/dual_check.dart b/client/lib/modules/dual_check/dual_check.dart
index 54f05e8..ec4f063 100644
--- a/client/lib/modules/dual_check/dual_check.dart
+++ b/client/lib/modules/dual_check/dual_check.dart
@@ -3,6 +3,7 @@
 // 通过 WebSocket 实时同步参与者列表 + 提交状态 + match 结果
 import 'dart:async';
 import 'dart:convert';
+import 'dart:html' if (dart.library.io) 'package:flutter/foundation.dart';
 
 import 'package:dio/dio.dart';
 import 'package:flutter/material.dart';
@@ -21,29 +22,62 @@ class DualCheck extends StatefulWidget {
   State<DualCheck> createState() => _DualCheckState();
 }
 
-class _DualCheckState extends State<DualCheck> {
-  final _api = DualCheckApi();
+class _DualCheckState extends State<DualCheck> with WidgetsBindingObserver {
+  final _api = DualCheckApi.instance;
   final _nickService = NicknameService.instance;
   final _textCtrl = TextEditingController();
 
   // ── 会话状态 ──
   String? _sessionId;
-  late String _nickname = '用户';
+  late String _nickname = '用户';       // 本地显示昵称（由 NicknameService 驱动）
+  String _serverNick = '';              // 服务端已知的昵称（与 server 同步）
   late _RoleSelect _myRole = _RoleSelect.initiator;
   SessionResp? _session; // 当前会话全量状态（发起方视图）
 
   // ── WS ──
   WebSocketChannel? _ws;
   StreamSubscription? _wsSub;
+  bool _wsStreamDone = false; // WS 底层 stream 是否已关闭
+
+  // ── 浏览器/APP 生命周期 ──
+  bool _pageHidden = false;   // 页面是否被隐藏过（paused）——用于识别浏览器手势返回等场景
+
+  // ── rename 失败回滚 ──
+  String? _renamePendingOldNick; // 发送 rename 前暂存当前昵称，若后端报错则回滚
+  String? _renamePendingNewNick; // 发送 rename 前暂存目标昵称，用于去重
 
   // ── UI 状态 ──
   bool _isLoading = false;
   String? _errorMsg;
+  String? _mySubmittedText; // 自己提交过的文本（发起方提交后展示用）
+  bool _initTextExpanded = false; // 发起方已提交文本是否展开
+  bool _sessionEndedShown = false; // 防重复弹 session_ended 弹窗
+  bool _mySubmitted = false; // 参与者：自己是否已提交
+  bool? _myMatch; // 参与者：自己的 match 结果（null=发起方还没提交）
+
+  StreamSubscription<String>? _nickSub;
 
   @override
   void initState() {
     super.initState();
+    WidgetsBinding.instance.addObserver(this);
+    _setupBrowserLifecycle();
     _loadNickname();
+    // 开启跨标签页同步（仅 Web 生效）
+    _nickService.enableCrossTabSync();
+    // 监听昵称变化（本地修改 + 其他标签页修改都会触发）
+    _nickSub = _nickService.onChanged.listen((n) {
+      if (!mounted) return;
+      final oldNick = _nickname;
+      setState(() => _nickname = n);
+      // 如果正在会话中且是参与者，通知后端改名
+      if (_sessionId != null && _myRole == _RoleSelect.participant && oldNick != n) {
+        debugPrint('[DC] onChanged: old=$oldNick new=$n sessionId=$_sessionId ws=$_ws');
+        _sendRename(n);
+      } else {
+        debugPrint('[DC] onChanged skip: sessionId=$_sessionId role=$_myRole old=$oldNick new=$n');
+      }
+    });
   }
 
   Future<void> _loadNickname() async {
@@ -54,17 +88,109 @@ class _DualCheckState extends State<DualCheck> {
 
   @override
   void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    _teardownBrowserLifecycle();
+    _nickSub?.cancel();
     _wsSub?.cancel();
     _ws?.sink.close();
     _textCtrl.dispose();
     super.dispose();
   }
 
+  // ── dart:html 浏览器事件监听（处理 Safari bfcache 手势返回恢复） ──
+  // visibilitychange：切 tab 触发（切走 hidden，切回 visible）
+  // pageshow：页面显示时触发（包括 bfcache 恢复！Safari 手势拉回来必触发）
+  // pagehide：页面隐藏时触发（包括 bfcache 冻结！Safari 手势后退必触发）
+  void _setupBrowserLifecycle() {
+    try {
+      // ignore: undefined_function —— dart:html 仅在 Web 编译时可用
+      document.onVisibilityChange.listen((_) {
+        final hidden = document.hidden ?? false;
+        debugPrint('[DC] html visibilitychange hidden=$hidden');
+        if (hidden) {
+          _pageHidden = true;
+        } else {
+          _checkAndExit();
+        }
+      });
+      // ignore: undefined_function
+      window.onPageShow.listen((e) {
+        // persisted=true 表示从 bfcache 恢复（Safari 手势拉回来的场景）
+        final persisted = (e as dynamic).persisted as bool? ?? false;
+        debugPrint('[DC] html pageshow persisted=$persisted pageHidden=$_pageHidden wsDone=$_wsStreamDone');
+        if (persisted) {
+          _pageHidden = true; // bfcache 恢复，标记为隐藏过
+        }
+        _checkAndExit();
+      });
+      // ignore: undefined_function
+      window.onPageHide.listen((e) {
+        final persisted = (e as dynamic).persisted as bool? ?? false;
+        debugPrint('[DC] html pagehide persisted=$persisted');
+        if (persisted) {
+          _pageHidden = true;
+        }
+      });
+      debugPrint('[DC] browser lifecycle listeners installed');
+    } catch (_) {
+      // 非 Web 平台（iOS/Android native）忽略
+      debugPrint('[DC] dart:html not available, skip browser lifecycle setup');
+    }
+  }
+
+  void _teardownBrowserLifecycle() {
+    try {
+      // ignore: undefined_function
+      document.onVisibilityChange.drain();
+      // ignore: undefined_function
+      window.onPageShow.drain();
+      // ignore: undefined_function
+      window.onPageHide.drain();
+    } catch (_) {}
+  }
+
+  // 统一的退出检查：只要"页面被浏览器隐藏过" + "WS 已断" → 强制退出
+  void _checkAndExit() {
+    if (_pageHidden && _wsStreamDone && _sessionId != null && mounted) {
+      debugPrint('[DC] _checkAndExit → force exit (pageHidden+wsDone)');
+      _reset();
+      Navigator.of(context).pop();
+    } else if (_pageHidden && _wsStreamDone) {
+      debugPrint('[DC] _checkAndExit: conditions met but not mounted or no session');
+    } else {
+      debugPrint('[DC] _checkAndExit: no exit. pageHidden=$_pageHidden wsDone=$_wsStreamDone session=$_sessionId');
+    }
+  }
+
+  // ── WidgetsBindingObserver 生命周期：识别浏览器手势返回后又恢复的场景 ──
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    if (state == AppLifecycleState.paused || state == AppLifecycleState.inactive) {
+      _pageHidden = true;
+      debugPrint('[DC] lifecycle: page hidden (paused/inactive)');
+    } else if (state == AppLifecycleState.resumed) {
+      debugPrint('[DC] lifecycle: page resumed, pageHidden=$_pageHidden wsDone=$_wsStreamDone session=$_sessionId');
+      if (_pageHidden) {
+        _pageHidden = false;
+        // 关键：页面被浏览器隐藏过（手势返回/切标签），恢复后 WS 已断 → 强制退出
+        if (_wsStreamDone && _sessionId != null) {
+          debugPrint('[DC] page was hidden + WS closed → force exit to home');
+          _reset();
+          if (mounted) {
+            Navigator.of(context).pop();
+          }
+        }
+      }
+    }
+  }
+
   // ── 发起方：创建会话 ──
   Future<void> _createSession() async {
     setState(() => _isLoading = true);
     try {
-      final resp = await _api.createSession(nickname: _nickname);
+      final bid = await _nickService.browserId;
+      final resp = await _api.createSession(nickname: _nickname, browserId: bid);
       setState(() {
         _sessionId = resp.sessionId;
         _myRole = _RoleSelect.initiator;
@@ -72,9 +198,9 @@ class _DualCheckState extends State<DualCheck> {
       // WS 连接（发起方不需要 join，直接连接）
       _connectWs();
     } on DioException catch (e) {
-      setState(() => _errorMsg = isBizError(e) ? bizErrorMessage(e) : '创建失败');
+      setState(() => _errorMsg = _friendlyError(e, '创建失败'));
     } catch (e) {
-      setState(() => _errorMsg = '创建失败：$e');
+      setState(() => _errorMsg = _friendlyError(e, '创建失败'));
     } finally {
       setState(() => _isLoading = false);
     }
@@ -96,6 +222,7 @@ class _DualCheckState extends State<DualCheck> {
             children: [
               TextField(
                 controller: ctrl,
+                autofocus: true,
                 enabled: !isChecking,
                 decoration: const InputDecoration(
                   hintText: '粘贴或输入会话码',
@@ -116,14 +243,20 @@ class _DualCheckState extends State<DualCheck> {
               child: const Text('取消'),
             ),
             FilledButton(
-              onPressed: isChecking
-                  ? null
-                  : () async {
-                      final sid = ctrl.text.trim();
+                      onPressed: isChecking
+                          ? null
+                          : () async {
+                      String sid = ctrl.text.trim();
                       if (sid.isEmpty) {
                         set(() => err = '请输入会话码');
                         return;
                       }
+                      // 如果粘贴的是 URL，尝试提取 session_id
+                      final extracted = _extractSessionId(sid);
+                      if (extracted != null) {
+                        sid = extracted;
+                        ctrl.text = sid;
+                      }
                       set(() {
                         isChecking = true;
                         err = null;
@@ -163,19 +296,32 @@ class _DualCheckState extends State<DualCheck> {
   }
 
   // ── WS 连接 ──
-  void _connectWs() {
+  Future<void> _connectWs() async {
     final role = _myRole == _RoleSelect.initiator ? 'initiator' : 'participant';
+    // 连接时用当前本地昵称；如果参与方被自动改名，server 会在 full_state 或 nickname_auto_changed 里通知
+    _serverNick = _nickname;
+    final bid = await _nickService.browserId;
     final url = _api.wsUrl(
       sessionId: _sessionId!,
       role: role,
       nickname: _nickname,
+      browserId: bid,
     );
     try {
       _ws = WebSocketChannel.connect(Uri.parse(url));
+      _wsStreamDone = false;
       _wsSub = _ws!.stream.listen(_onWsMessage, onError: (e) {
         debugPrint('[DC] ws error: $e');
       }, onDone: () {
-        debugPrint('[DC] ws closed');
+        debugPrint('[DC] ws stream done (closed)');
+        _wsStreamDone = true;
+        // 兜底：如果页面之前已被隐藏过（Safari 手势后退 bfcache 场景），
+        // WS onDone 可能在 resumed 之后才触发（时序问题），这里立即退出
+        if (_pageHidden && _sessionId != null && mounted) {
+          debugPrint('[DC] ws done after page hidden → force exit');
+          _reset();
+          Navigator.of(context).pop();
+        }
       });
     } catch (e) {
       debugPrint('[DC] ws connect fail: $e');
@@ -183,14 +329,28 @@ class _DualCheckState extends State<DualCheck> {
   }
 
   // ── WS 消息处理（事件驱动 UI） ──
-  void _onWsMessage(dynamic raw) {
+  Future<void> _onWsMessage(dynamic raw) async {
     try {
-      final msg = WSMessage.fromJson(
-          jsonDecode(raw as String) as Map<String, dynamic>);
+      final msg = WSMessage.fromJson(raw as String);
       switch (msg.type) {
         case 'full_state':
           final s = DualCheckApi.parseSession(msg.data);
-          setState(() => _session = s);
+          // 在参与者列表中找到自己，提取 match 结果
+          bool? myMatch;
+          for (final p in s.participants) {
+            if (p.nickname == _nickname && p.match != null) {
+              myMatch = p.match;
+              break;
+            }
+          }
+          setState(() {
+            _session = s;
+            if (myMatch != null) _myMatch = myMatch;
+          });
+          // 如果之前已提交但发起方后来才提交 → 弹结果
+          if (_mySubmitted && myMatch != null) {
+            _showMyResult(myMatch);
+          }
         case 'participant_joined':
           final nick = msg.data['nickname'] as String;
           setState(() {
@@ -199,6 +359,7 @@ class _DualCheckState extends State<DualCheck> {
                 initiatorNickname: '',
                 initiatorReady: false,
                 allowResubmit: false,
+                ignoreWs: false,
                 participants: [],
                 ttlSeconds: 0);
             final list = List<ParticipantResp>.from(_session!.participants);
@@ -245,14 +406,105 @@ class _DualCheckState extends State<DualCheck> {
                 initiatorNickname: '',
                 initiatorReady: false,
                 allowResubmit: false,
+                ignoreWs: false,
                 participants: [],
                 ttlSeconds: 0);
             _session = _session!.copyWith(allowResubmit: allow);
-            if (allow) _errorMsg = null; // 开关打开时清掉上次"不能重提交"的报错
+            if (allow) _errorMsg = null;
+          });
+        case 'ignore_ws_changed':
+          final ignore = msg.data['ignore'] as bool;
+          setState(() {
+            _session ??= SessionResp(
+                sessionId: _sessionId!,
+                initiatorNickname: '',
+                initiatorReady: false,
+                allowResubmit: false,
+                ignoreWs: false,
+                participants: [],
+                ttlSeconds: 0);
+            _session = _session!.copyWith(ignoreWs: ignore);
           });
         case 'session_ended':
           // 只有参与者收到才弹窗——发起方自己就是结束者，不需要再提示自己
           if (_myRole == _RoleSelect.participant) _showSessionEnded();
+        case 'participant_nickname_changed':
+          final oldNick = msg.data['old_nickname'] as String;
+          final newNick = msg.data['new_nickname'] as String;
+          setState(() {
+            if (_session == null) return;
+            final list = List<ParticipantResp>.from(_session!.participants);
+            final idx = list.indexWhere((p) => p.nickname == oldNick);
+            if (idx >= 0) {
+              list[idx] = list[idx].copyWith(nickname: newNick);
+              _session = _session!.copyWith(participants: list);
+            }
+          });
+          // 如果改名的是自己，更新 _serverNick 并清 pending
+          if (_myRole == _RoleSelect.participant &&
+              (_renamePendingNewNick == newNick || _serverNick == oldNick)) {
+            _serverNick = newNick;
+            _renamePendingOldNick = null;
+            _renamePendingNewNick = null;
+          }
+        case 'nickname_auto_changed':
+          // 服务端因昵称冲突自动改名，只发给改名的那个客户端
+          final newNick = msg.data['nickname'] as String;
+          final oldNick = _nickname;
+          debugPrint('[DC] nickname auto changed: $oldNick → $newNick');
+          setState(() {
+            _nickname = newNick;
+            _serverNick = newNick; // 服务端已经用这个名字了
+            _nickService.setNickname(newNick); // 持久化
+            // 如果 _session 已初始化，更新自己在 participants 里的记录
+            if (_session != null) {
+              final list = List<ParticipantResp>.from(_session!.participants);
+              final idx = list.indexWhere((p) => p.nickname == oldNick);
+              if (idx >= 0) {
+                list[idx] = list[idx].copyWith(nickname: newNick);
+                _session = _session!.copyWith(participants: list);
+              }
+            }
+          });
+          if (mounted) {
+            ScaffoldMessenger.of(context).showSnackBar(
+              _snack('🔔 昵称冲突，已自动改为 $newNick'),
+            );
+          }
+        case 'error':
+          final errMsg = msg.error;
+          if (errMsg.isNotEmpty) {
+            debugPrint('[DC] ws error from server: $errMsg');
+            // 如果是 rename 请求期间收到的错误，回滚本地昵称
+            bool needRollback = _renamePendingOldNick != null;
+            final rollbackTo = _renamePendingOldNick;
+            final pendingNew = _renamePendingNewNick;
+            _renamePendingOldNick = null;
+            _renamePendingNewNick = null;
+
+            if (needRollback && rollbackTo != null) {
+              debugPrint('[DC] rename failed, rolling back to: $rollbackTo');
+              setState(() {
+                _nickname = rollbackTo;
+                _serverNick = rollbackTo; // 恢复 serverNick
+                _nickService.setNickname(rollbackTo); // 不 await，避免阻塞 SnackBar
+                // 如果 _session 的 participants 里有 pending 的新昵称，恢复回来
+                if (_session != null && pendingNew != null) {
+                  final list = List<ParticipantResp>.from(_session!.participants);
+                  final idx = list.indexWhere((p) => p.nickname == pendingNew);
+                  if (idx >= 0) {
+                    list[idx] = list[idx].copyWith(nickname: rollbackTo);
+                    _session = _session!.copyWith(participants: list);
+                  }
+                }
+              });
+            }
+            if (_sessionId != null && mounted) {
+              ScaffoldMessenger.of(context).showSnackBar(
+                _snack(errMsg, icon: Icons.error_outline, color: Colors.red),
+              );
+            }
+          }
       }
     } catch (e) {
       debugPrint('[DC] ws parse error: $e');
@@ -262,7 +514,7 @@ class _DualCheckState extends State<DualCheck> {
   // ── 提交文本 ──
   Future<void> _submit() async {
     if (_sessionId == null) return;
-    final text = _textCtrl.text.trim();
+    final text = _textCtrl.text;
     if (text.isEmpty) {
       setState(() => _errorMsg = '请输入内容后再提交');
       return;
@@ -279,7 +531,8 @@ class _DualCheckState extends State<DualCheck> {
         role: role,
         text: text,
       );
-      _textCtrl.clear();
+      // 只清发起方的输入框（发起方提交后有只读预览卡片展示文本，参与者要保留原输入方便重提）
+      if (_myRole == _RoleSelect.initiator) _textCtrl.clear();
 
       // 参与者提交后立刻在本地更新会话状态
       if (_myRole == _RoleSelect.participant) {
@@ -289,24 +542,22 @@ class _DualCheckState extends State<DualCheck> {
               initiatorNickname: '',
               initiatorReady: false,
               allowResubmit: false,
+              ignoreWs: false,
               participants: [],
               ttlSeconds: 0);
           _session = _session!.copyWith(
             initiatorReady: resp.initiatorReady,
           );
+          _mySubmitted = true;
+          _myMatch = resp.match; // null 表示发起方还没提交
         });
-        // 如果 initiator 已提交，可以直接显示 match
+        // 如果 initiator 已提交，可以直接显示 match 弹窗
         if (resp.initiatorReady && resp.match != null) {
           _showMyResult(resp.match!);
-        } else {
-          _showParticipantWaiting();
         }
       } else {
-        // 发起方提交后等 WS full_state 来刷新
-        if (!mounted) return;
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('标准答案已提交，等待参与者...')),
-        );
+        // 发起方提交后等 WS full_state 来刷新；同时保存自己的文本用于只读展示
+        setState(() => _mySubmittedText = text);
       }
     } on DioException catch (e) {
       final code = bizErrorCode(e);
@@ -324,17 +575,81 @@ class _DualCheckState extends State<DualCheck> {
     }
   }
 
+  // 从粘贴的 URL/文本中提取会话码
+  // 支持的格式：
+  //   http://host/?session_id=M_xxx
+  //   http://host/api/v1/dual-check/session/M_xxx
+  //   /api/v1/dual-check/session/M_xxx
+  //   session_id=M_xxx
+  //   M_xxx → 原样返回 null（不是 URL）
+  String? _extractSessionId(String input) {
+    // 1. 先试 query param
+    try {
+      final uri = Uri.tryParse(input);
+      if (uri != null) {
+        if (uri.queryParameters['session_id'] case final sid?) return sid;
+        // 2. 再试 path 里的 session/XXX 或 check/XXX 段
+        final segs = uri.pathSegments;
+        for (int i = 0; i < segs.length - 1; i++) {
+          if (segs[i] == 'session' || segs[i] == 'check') return segs[i + 1];
+        }
+      }
+    } catch (_) {}
+    // 3. 纯文本匹配 session_id=XXX
+    final m = RegExp(r'session[_\-]?id=([^\s&]+)', caseSensitive: false).firstMatch(input);
+    if (m != null) return m.group(1);
+    return null;
+  }
+
+  // 通过 WS 发送 rename 消息（仅参与者用）
+  void _sendRename(String newNick) {
+    if (_ws == null) {
+      debugPrint('[DC] _sendRename SKIP: ws is null');
+      return;
+    }
+    // 重要：必须和 _serverNick 比较，不能和 _nickname 比。
+    // 因为 _nickService.setNickname() 会同步触发 onChanged 把 _nickname 改成 newNick，
+    // 这时再和 _nickname 比永远相等，WS 消息就发不出去了。
+    if (newNick == _serverNick) {
+      debugPrint('[DC] _sendRename SKIP: same as server-known nick ($_serverNick)');
+      return;
+    }
+    // 暂存旧昵称，用于后端报错时回滚
+    _renamePendingOldNick = _serverNick; // 用 serverNick 而不是 _nickname
+    _renamePendingNewNick = newNick;
+    try {
+      final msg = jsonEncode({
+        'type': 'rename',
+        'data': {'new_nickname': newNick},
+      });
+      debugPrint('[DC] _sendRename → $msg');
+      _ws!.sink.add(msg);
+    } catch (e) {
+      debugPrint('[DC] _sendRename FAIL: $e');
+      _renamePendingOldNick = null;
+      _renamePendingNewNick = null;
+    }
+  }
+
   // ── 重置 ──
   void _reset() {
     _wsSub?.cancel();
     _ws?.sink.close();
     _textCtrl.clear();
+    _renamePendingOldNick = null;
+    _renamePendingNewNick = null;
+    _serverNick = '';
     setState(() {
       _ws = null;
       _wsSub = null;
       _sessionId = null;
       _session = null;
       _errorMsg = null;
+      _mySubmittedText = null;
+      _initTextExpanded = false;
+      _sessionEndedShown = false;
+      _mySubmitted = false;
+      _myMatch = null;
     });
   }
 
@@ -378,13 +693,12 @@ class _DualCheckState extends State<DualCheck> {
   }
 
   // ── 收到 session_ended WS 事件：弹窗 + 自动退出 ──
-  void _showSessionEnded() {
-    // 防重复弹窗（多次 session_ended / 重复 Build）
-    if (!mounted || _sessionId == null) return;
+  void _showSessionEnded() async {
+    // 防重复：收到多个 session_ended / 重复触发都只弹一次
+    if (!mounted || _sessionId == null || _sessionEndedShown) return;
+    _sessionEndedShown = true;
     final sid = _sessionId!;
-    _reset();
-    if (!mounted) return;
-    showDialog(
+    await showDialog(
       context: context,
       barrierDismissible: false,
       builder: (ctx) => AlertDialog(
@@ -399,6 +713,8 @@ class _DualCheckState extends State<DualCheck> {
         ],
       ),
     );
+    if (!mounted) return;
+    _reset();
   }
 
   // ── 发起方：切换允许重提交开关 ──
@@ -419,7 +735,28 @@ class _DualCheckState extends State<DualCheck> {
         _session = _session?.copyWith(allowResubmit: !value);
       });
       ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text('操作失败：${bizErrorMessage(e)}')),
+        _snack('操作失败：${bizErrorMessage(e)}', icon: Icons.error_outline, color: Colors.red),
+      );
+    }
+  }
+
+  Future<void> _toggleIgnoreWs(bool value) async {
+    final sid = _sessionId;
+    if (sid == null) return;
+    setState(() {
+      _session = _session?.copyWith(ignoreWs: value);
+    });
+    try {
+      final sess = await _api.setIgnoreWs(sid, ignore: value);
+      if (!mounted) return;
+      setState(() => _session = sess);
+    } on DioException catch (e) {
+      if (!mounted) return;
+      setState(() {
+        _session = _session?.copyWith(ignoreWs: !value);
+      });
+      ScaffoldMessenger.of(context).showSnackBar(
+        _snack('操作失败：${bizErrorMessage(e)}', icon: Icons.error_outline, color: Colors.red),
       );
     }
   }
@@ -427,12 +764,14 @@ class _DualCheckState extends State<DualCheck> {
   // ── 设置昵称对话框 ──
   void _showNicknameDialog() {
     final ctrl = TextEditingController(text: _nickname);
+    final capturedOldNick = _nickname; // 捕获旧昵称（setNickname 是异步的，onChanged 也会 set，这里做个备份）
     showDialog(
       context: context,
       builder: (ctx) => AlertDialog(
         title: const Text('设置昵称'),
         content: TextField(
           controller: ctrl,
+          autofocus: true,
           maxLength: 32,
           decoration: const InputDecoration(
             hintText: '1-32 字符',
@@ -447,16 +786,23 @@ class _DualCheckState extends State<DualCheck> {
           ),
           FilledButton(
             onPressed: () async {
-              final ok = await _nickService.setNickname(ctrl.text);
+              final newNick = ctrl.text.trim();
+              final ok = await _nickService.setNickname(newNick);
               if (ok && ctx.mounted) Navigator.pop(ctx);
               setState(() {
-                if (ok) _nickname = ctrl.text.trim();
+                if (ok) _nickname = newNick;
               });
               if (ctx.mounted && !ok) {
                 ScaffoldMessenger.of(ctx).showSnackBar(
-                  const SnackBar(content: Text('昵称无效')),
+                  _snack('昵称无效', icon: Icons.error_outline, color: Colors.red),
                 );
               }
+              // 双保险：保存成功后直接通知后端（不管 onChanged 有没有触发）
+              if (ok && capturedOldNick != newNick &&
+                  _sessionId != null && _myRole == _RoleSelect.participant) {
+                debugPrint('[DC] dialog save: old=$capturedOldNick new=$newNick → _sendRename');
+                _sendRename(newNick);
+              }
             },
             child: const Text('保存'),
           ),
@@ -474,7 +820,6 @@ class _DualCheckState extends State<DualCheck> {
             size: 60, color: match ? Colors.green : Colors.red),
         title: Text(match ? '🎉 完全一致' : '❌ 不相同',
             style: TextStyle(color: match ? Colors.green : Colors.red)),
-        content: Text('你的昵称：$_nickname'),
         actions: [
           TextButton(
               onPressed: () => Navigator.pop(ctx),
@@ -484,12 +829,6 @@ class _DualCheckState extends State<DualCheck> {
     );
   }
 
-  void _showParticipantWaiting() {
-    ScaffoldMessenger.of(context).showSnackBar(
-      const SnackBar(content: Text('已提交，等待发起方确认答案...')),
-    );
-  }
-
   // ── UI ──
   @override
   Widget build(BuildContext context) {
@@ -518,11 +857,13 @@ class _DualCheckState extends State<DualCheck> {
         title: const Text('DualCheck 双验'),
         centerTitle: true,
         actions: [
-          IconButton(
-            tooltip: '设置昵称',
-            icon: const Icon(Icons.person),
-            onPressed: _showNicknameDialog,
-          ),
+          // 发起者进入会话后，不允许修改发起者昵称，隐藏按钮
+          if (_sessionId == null || _myRole != _RoleSelect.initiator)
+            IconButton(
+              tooltip: '设置昵称',
+              icon: const Icon(Icons.person),
+              onPressed: _showNicknameDialog,
+            ),
         ],
       ),
       body: body,
@@ -584,27 +925,6 @@ class _DualCheckState extends State<DualCheck> {
             textAlign: TextAlign.center,
             style: TextStyle(color: Colors.grey)),
         const SizedBox(height: 24),
-        Container(
-          padding: const EdgeInsets.all(12),
-          decoration: BoxDecoration(
-            color: Colors.grey.shade100,
-            borderRadius: BorderRadius.circular(8),
-          ),
-          child: Row(
-            children: [
-              const Icon(Icons.person, color: Colors.grey),
-              const SizedBox(width: 8),
-              const Text('当前昵称：'),
-              Text(_nickname,
-                  style: const TextStyle(fontWeight: FontWeight.bold)),
-              const Spacer(),
-              TextButton(
-                onPressed: _showNicknameDialog,
-                child: const Text('修改'),
-              ),
-            ],
-          ),
-        ),
         const Spacer(),
         ElevatedButton.icon(
           onPressed: _isLoading ? null : _createSession,
@@ -645,103 +965,161 @@ class _DualCheckState extends State<DualCheck> {
     return Column(
       crossAxisAlignment: CrossAxisAlignment.stretch,
       children: [
-        _buildSessionBar(),
-        const SizedBox(height: 16),
-        // 发起方输入框（标准答案）
-        if (!initReady) ...[
-          TextField(
-            controller: _textCtrl,
-            maxLines: 4,
-            maxLength: 10000,
-            decoration: const InputDecoration(
-              hintText: '请输入你的答案（标准答案）...',
-              border: OutlineInputBorder(),
-            ),
-          ),
-          const SizedBox(height: 12),
-          ElevatedButton(
-            onPressed: _isLoading ? null : _submit,
-            child: _isLoading
-                ? const CircularProgressIndicator(strokeWidth: 2, color: Colors.white)
-                : const Text('提交标准答案'),
-          ),
-          if (_errorMsg != null) _buildError(_errorMsg!),
-        ] else ...[
-          Container(
-            padding: const EdgeInsets.all(12),
-            decoration: BoxDecoration(
-              color: Colors.green.shade50,
-              borderRadius: BorderRadius.circular(8),
-            ),
-            child: Row(
+        // ── 上半部分：可滚 ──
+        Expanded(
+          child: SingleChildScrollView(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
               children: [
-                Icon(Icons.check_circle, color: Colors.green.shade700),
-                const SizedBox(width: 8),
-                Expanded(
-                  child: Text('标准答案已提交（$initNick）',
-                      style: TextStyle(color: Colors.green.shade700)),
+                _buildSessionBar(),
+                const SizedBox(height: 16),
+                if (!initReady) ...[
+                  TextField(
+                    controller: _textCtrl,
+                    maxLines: 4,
+                    maxLength: 10000,
+                    decoration: const InputDecoration(
+                      hintText: '请输入你的答案（标准答案）...',
+                      border: OutlineInputBorder(),
+                    ),
+                  ),
+                  const SizedBox(height: 12),
+                  ElevatedButton(
+                    onPressed: _isLoading ? null : _submit,
+                    child: _isLoading
+                        ? const CircularProgressIndicator(strokeWidth: 2, color: Colors.white)
+                        : const Text('提交标准答案'),
+                  ),
+                  if (_errorMsg != null) _buildError(_errorMsg!),
+                ] else ...[
+                  Container(
+                    decoration: BoxDecoration(
+                      color: Colors.green.shade50,
+                      borderRadius: BorderRadius.circular(8),
+                      border: Border.all(color: Colors.green.shade200),
+                    ),
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.stretch,
+                      children: [
+                        Padding(
+                          padding: const EdgeInsets.fromLTRB(12, 10, 8, 6),
+                          child: Row(
+                            children: [
+                              Icon(Icons.check_circle, color: Colors.green.shade700, size: 18),
+                              const SizedBox(width: 6),
+                              Expanded(
+                                child: Text('标准答案已提交（$initNick）',
+                                    style: TextStyle(
+                                        color: Colors.green.shade700,
+                                        fontWeight: FontWeight.w600)),
+                              ),
+                              if (_mySubmittedText != null && _mySubmittedText!.length > 80)
+                                TextButton.icon(
+                                  onPressed: () =>
+                                      setState(() => _initTextExpanded = !_initTextExpanded),
+                                  icon: Icon(
+                                    _initTextExpanded
+                                        ? Icons.expand_less
+                                        : Icons.expand_more,
+                                    size: 18,
+                                  ),
+                                  label: Text(_initTextExpanded ? '收起' : '展开'),
+                                  style: TextButton.styleFrom(
+                                      padding: EdgeInsets.zero,
+                                      minimumSize: Size.zero,
+                                      tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                                      foregroundColor: Colors.green.shade700),
+                                ),
+                              if (_mySubmittedText != null && _mySubmittedText!.isNotEmpty)
+                                IconButton(
+                                  tooltip: '复制内容',
+                                  icon: Icon(Icons.copy, size: 18, color: Colors.green.shade700),
+                                  padding: EdgeInsets.zero,
+                                  constraints: const BoxConstraints(),
+                                  onPressed: () => _copy(_mySubmittedText!),
+                                ),
+                            ],
+                          ),
+                        ),
+                        if (_mySubmittedText != null)
+                          Container(
+                            padding: const EdgeInsets.fromLTRB(12, 0, 12, 12),
+                            child: Text(
+                              _mySubmittedText!,
+                              maxLines: _initTextExpanded ? null : 6,
+                              style: TextStyle(
+                                  color: Colors.green.shade900, height: 1.5),
+                            ),
+                          ),
+                      ],
+                    ),
+                  ),
+                ],
+                const SizedBox(height: 24),
+                Row(
+                  children: [
+                    const Text('参与者',
+                        style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold)),
+                    const Spacer(),
+                    Container(
+                      padding:
+                          const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
+                      decoration: BoxDecoration(
+                        color: Colors.blue.shade100,
+                        borderRadius: BorderRadius.circular(12),
+                      ),
+                      child: Text('${participants.length} 人',
+                          style: TextStyle(
+                              color: Colors.blue.shade800,
+                              fontSize: 12,
+                              fontWeight: FontWeight.bold)),
+                    ),
+                  ],
                 ),
+                const SizedBox(height: 8),
+                if (participants.isEmpty)
+                  Container(
+                    height: 160,
+                    alignment: Alignment.center,
+                    child: Column(
+                      mainAxisSize: MainAxisSize.min,
+                      children: [
+                        Icon(Icons.group_outlined,
+                            size: 48, color: Colors.grey.shade300),
+                        const SizedBox(height: 8),
+                        const Text('暂无参与者，把会话码分享给他们吧',
+                            style: TextStyle(color: Colors.grey)),
+                      ],
+                    ),
+                  )
+                else
+                  SizedBox(
+                    height: 200,
+                    child: ListView.separated(
+                      itemCount: participants.length,
+                      separatorBuilder: (_, _) => const SizedBox(height: 8),
+                      itemBuilder: (_, i) =>
+                          _buildParticipantCard(participants[i]),
+                    ),
+                  ),
+                const SizedBox(height: 16),
               ],
             ),
           ),
-        ],
-        const SizedBox(height: 24),
-
-        // 参与者列表
-        Row(
-          children: [
-            const Text('参与者',
-                style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold)),
-            const Spacer(),
-            Container(
-              padding:
-                  const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
-              decoration: BoxDecoration(
-                color: Colors.blue.shade100,
-                borderRadius: BorderRadius.circular(12),
-              ),
-              child: Text('${participants.length} 人',
-                  style: TextStyle(
-                      color: Colors.blue.shade800,
-                      fontSize: 12,
-                      fontWeight: FontWeight.bold)),
-            ),
-          ],
         ),
-        const SizedBox(height: 8),
-        if (participants.isEmpty)
-          Expanded(
-            child: Center(
-              child: Column(
-                mainAxisSize: MainAxisSize.min,
-                children: [
-                  Icon(Icons.group_outlined,
-                      size: 48, color: Colors.grey.shade300),
-                  const SizedBox(height: 8),
-                  const Text('暂无参与者，把会话码分享给他们吧',
-                      style: TextStyle(color: Colors.grey)),
-                ],
-              ),
-            ),
-          )
-        else
-          Expanded(
-            child: ListView.separated(
-              itemCount: participants.length,
-              separatorBuilder: (_, _) => const SizedBox(height: 8),
-              itemBuilder: (_, i) =>
-                  _buildParticipantCard(participants[i]),
-            ),
-          ),
-
-        // 发起方控制区
+        // ── 底部控制区：永远贴底 ──
         SwitchListTile.adaptive(
           contentPadding: const EdgeInsets.symmetric(horizontal: 4),
           title: const Text('允许参与者重新提交'),
-          subtitle: const Text('开启后参与者可以覆盖之前的提交结果'),
           value: _session?.allowResubmit ?? false,
           onChanged: _toggleResubmit,
         ),
+        SwitchListTile.adaptive(
+          contentPadding: const EdgeInsets.symmetric(horizontal: 4),
+          title: const Text('比对时忽略首尾空白'),
+          value: _session?.ignoreWs ?? false,
+          onChanged: _toggleIgnoreWs,
+        ),
         const SizedBox(height: 8),
         ElevatedButton(onPressed: _confirmAndEndSession, child: const Text('结束会话')),
       ],
@@ -843,6 +1221,44 @@ class _DualCheckState extends State<DualCheck> {
         ),
         const SizedBox(height: 16),
 
+        // 自己的状态条（提交后显示）
+        if (_mySubmitted)
+          Container(
+            padding: const EdgeInsets.all(12),
+            decoration: BoxDecoration(
+              color: _myMatch == null
+                  ? Colors.blue.shade50
+                  : (_myMatch! ? Colors.green.shade50 : Colors.red.shade50),
+              borderRadius: BorderRadius.circular(8),
+            ),
+            child: Row(
+              children: [
+                Icon(
+                    _myMatch == null
+                        ? Icons.hourglass_empty
+                        : (_myMatch! ? Icons.check_circle : Icons.cancel),
+                    color: _myMatch == null
+                        ? Colors.blue
+                        : (_myMatch! ? Colors.green : Colors.red)),
+                const SizedBox(width: 8),
+                Expanded(
+                  child: Text(
+                    _myMatch == null
+                        ? '已提交，等待发起方提交标准答案后比对...'
+                        : (_myMatch! ? '✅ 你的答案和发起方完全一致' : '❌ 你的答案和发起方不一致'),
+                    style: TextStyle(
+                        color: _myMatch == null
+                            ? Colors.blue.shade700
+                            : (_myMatch!
+                                ? Colors.green.shade700
+                                : Colors.red.shade700)),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        if (_mySubmitted) const SizedBox(height: 16),
+
         // 自己的输入框
         TextField(
           controller: _textCtrl,
@@ -864,7 +1280,30 @@ class _DualCheckState extends State<DualCheck> {
         if (_errorMsg != null) _buildError(_errorMsg!),
 
         const Spacer(),
-        ElevatedButton(onPressed: _reset, child: const Text('离开会话')),
+        ElevatedButton(
+          onPressed: () async {
+            final ok = await showDialog<bool>(
+              context: context,
+              builder: (ctx) => AlertDialog(
+                icon: const Icon(Icons.exit_to_app, size: 40, color: Colors.blue),
+                title: const Text('确定离开会话？'),
+                content: const Text('离开后将断开连接，不再接收会话消息。'),
+                actions: [
+                  TextButton(
+                    onPressed: () => Navigator.pop(ctx, false),
+                    child: const Text('取消'),
+                  ),
+                  FilledButton(
+                    onPressed: () => Navigator.pop(ctx, true),
+                    child: const Text('离开'),
+                  ),
+                ],
+              ),
+            );
+            if (ok == true && mounted) _reset();
+          },
+          child: const Text('离开会话'),
+        ),
       ],
     );
   }
@@ -922,7 +1361,28 @@ class _DualCheckState extends State<DualCheck> {
     await Clipboard.setData(ClipboardData(text: text));
     if (!mounted) return;
     ScaffoldMessenger.of(context)
-        .showSnackBar(const SnackBar(content: Text('已复制')));
+        .showSnackBar(_snack('已复制', icon: Icons.check_circle, color: Colors.green));
+  }
+
+  /// 统一的 SnackBar：圆角 + 图标 + 主题色
+  SnackBar _snack(String text, {IconData? icon, Color? color, Duration duration = const Duration(seconds: 2)}) {
+    final bg = color ?? Colors.grey.shade800;
+    return SnackBar(
+      content: Row(
+        children: [
+          if (icon != null) ...[
+            Icon(icon, color: Colors.white, size: 20),
+            const SizedBox(width: 8),
+          ],
+          Expanded(child: Text(text, style: const TextStyle(color: Colors.white))),
+        ],
+      ),
+      backgroundColor: bg,
+      behavior: SnackBarBehavior.floating,
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+      duration: duration,
+    );
   }
 
   Widget _buildError(String msg) {
@@ -969,6 +1429,7 @@ extension _SessionCopy on SessionResp {
     String? initiatorNickname,
     bool? initiatorReady,
     bool? allowResubmit,
+    bool? ignoreWs,
     List<ParticipantResp>? participants,
     int? ttlSeconds,
   }) {
@@ -977,8 +1438,29 @@ extension _SessionCopy on SessionResp {
       initiatorNickname: initiatorNickname ?? this.initiatorNickname,
       initiatorReady: initiatorReady ?? this.initiatorReady,
       allowResubmit: allowResubmit ?? this.allowResubmit,
+      ignoreWs: ignoreWs ?? this.ignoreWs,
       participants: participants ?? this.participants,
       ttlSeconds: ttlSeconds ?? this.ttlSeconds,
     );
   }
 }
+
+// ── 全局辅助：把 DioException 转成用户友好的提示 ──
+String _friendlyError(Object e, String fallback) {
+  if (e is DioException) {
+    switch (e.type) {
+      case DioExceptionType.connectionError:
+      case DioExceptionType.connectionTimeout:
+      case DioExceptionType.sendTimeout:
+      case DioExceptionType.receiveTimeout:
+        return '无法连接到服务器';
+      case DioExceptionType.cancel:
+        return '请求已取消';
+      case DioExceptionType.badResponse:
+        return isBizError(e) ? bizErrorMessage(e) : '服务器返回错误';
+      default:
+        return isBizError(e) ? bizErrorMessage(e) : fallback;
+    }
+  }
+  return '$fallback：$e';
+}
diff --git a/client/lib/modules/dual_check/nickname_service.dart b/client/lib/modules/dual_check/nickname_service.dart
index 6c5bfce..d4c3731 100644
--- a/client/lib/modules/dual_check/nickname_service.dart
+++ b/client/lib/modules/dual_check/nickname_service.dart
@@ -1,8 +1,13 @@
 // 全局昵称设置
 // 持久化到 SharedPreferences / localStorage，所有工具共享同一个昵称
+// Web 平台自动监听 localStorage 变化 → 跨标签页实时同步
+import 'dart:async';
+import 'dart:html' as html show window, StorageEvent;
+import 'package:flutter/foundation.dart' show kIsWeb;
 import 'package:shared_preferences/shared_preferences.dart';
 
 const _keyNickname = 'toolbox.nickname';
+const _keyBrowserId = 'toolbox.browser_id';
 
 class NicknameService {
   NicknameService._();
@@ -10,8 +15,60 @@ class NicknameService {
 
   SharedPreferences? _prefs;
 
+  /// 浏览器唯一 ID：同浏览器跨 tab 共享（localStorage 作用域），跨浏览器不同
+  /// 用于后端识别"同一个人"，避免昵称冲突时自动改名
+  String? _browserId;
+
+  /// 昵称变化广播流：本地 setNickname 触发 + Web 上其他标签页修改也触发
+  final _streamController = StreamController<String>.broadcast();
+  Stream<String> get onChanged => _streamController.stream;
+
+  StreamSubscription? _webStorageSub;
+
   Future<void> _ensureInit() async {
     _prefs ??= await SharedPreferences.getInstance();
+    // 惰性生成 browserId：首次访问时若没有就生成 uuid 存起来
+    if (_browserId == null) {
+      final existing = _prefs!.getString(_keyBrowserId);
+      if (existing != null && existing.isNotEmpty) {
+        _browserId = existing;
+      } else {
+        _browserId = _genBrowserId();
+        await _prefs!.setString(_keyBrowserId, _browserId!);
+      }
+    }
+  }
+
+  /// 获取浏览器 ID（稳定值，同浏览器跨 tab 相同）
+  Future<String> get browserId async {
+    await _ensureInit();
+    return _browserId!;
+  }
+
+  /// 生成短 browserId：base62（0-9A-Za-z），去掉特殊字符方便 URL 使用
+  /// 12 字符足够唯一（62^12 ≈ 3e21 种可能）
+  String _genBrowserId() {
+    const chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
+    final rand = DateTime.now().microsecond.hashCode;
+    final buf = StringBuffer();
+    int seed = rand ^ DateTime.now().millisecondsSinceEpoch;
+    for (int i = 0; i < 12; i++) {
+      seed = (seed * 1103515245 + 12345) & 0x7FFFFFFF;
+      buf.write(chars[seed % chars.length]);
+    }
+    return buf.toString();
+  }
+
+  /// 开启跨标签页同步（仅 Web 生效；非 Web 空操作）
+  /// 在 widget 的 initState 里调用一次即可
+  void enableCrossTabSync() {
+    if (!kIsWeb || _webStorageSub != null) return;
+    _webStorageSub = html.window.onStorage.listen((html.StorageEvent event) async {
+      if (event.key == _keyNickname) {
+        final n = await nickname;
+        _streamController.add(n);
+      }
+    });
   }
 
   /// 获取当前昵称，未设置时返回默认昵称
@@ -28,6 +85,12 @@ class NicknameService {
     if (trimmed.isEmpty || trimmed.length > 32) return false;
     await _ensureInit();
     await _prefs!.setString(_keyNickname, trimmed);
+    _streamController.add(trimmed);
     return true;
   }
+
+  void dispose() {
+    _webStorageSub?.cancel();
+    _webStorageSub = null;
+  }
 }
diff --git a/server/cmd/server/server b/server/cmd/server/server
new file mode 100755
index 0000000..f47c293
Binary files /dev/null and b/server/cmd/server/server differ
diff --git a/server/configs/config.go b/server/configs/config.go
index 700a7f6..b8ab0b1 100644
--- a/server/configs/config.go
+++ b/server/configs/config.go
@@ -77,7 +77,7 @@ func Load(configPath ...string) (*Config, error) {
 	v.SetDefault("rate_limit.global_rps", 1000)
 	v.SetDefault("rate_limit.per_ip_rps", 50)
 	v.SetDefault("rate_limit.burst", 100)
-	v.SetDefault("session.ttl", 900)
+	v.SetDefault("session.ttl", 604800)
 	v.SetDefault("session.max_text_length", 10000)
 	v.SetDefault("log.level", "info")
 	v.SetDefault("log.format", "json")
diff --git a/server/configs/config.yaml b/server/configs/config.yaml
index 0b8f94b..28c7f2b 100644
--- a/server/configs/config.yaml
+++ b/server/configs/config.yaml
@@ -21,7 +21,7 @@ rate_limit:
   burst: 100
 
 session:
-  ttl: 900                  # 会话过期时间（秒），默认 15 分钟
+  ttl: 604800                # 会话 Redis TTL（秒），默认 7 天。实际生命周期由发起方在线决定（发起方断开即结束），TTL 只是兜底防止发起方异常下线时 Redis 泄漏
   max_text_length: 10000    # 单条文本最大长度
 
 log:
diff --git a/server/internal/response/response.go b/server/internal/response/response.go
index 201d676..8d89897 100644
--- a/server/internal/response/response.go
+++ b/server/internal/response/response.go
@@ -118,3 +118,32 @@ func WSResubmitChanged(allow bool) WebSocketMessage {
 		Data: map[string]bool{"allow": allow},
 	}
 }
+
+// WSIgnoreWsChanged 发起方切换了"忽略首尾空白"开关
+func WSIgnoreWsChanged(ignore bool) WebSocketMessage {
+	return WebSocketMessage{
+		Type: "ignore_ws_changed",
+		Data: map[string]bool{"ignore": ignore},
+	}
+}
+
+// WSParticipantRenamed 参与者修改了昵称（old → new）
+func WSParticipantRenamed(oldNick, newNick string) WebSocketMessage {
+	return WebSocketMessage{
+		Type: "participant_nickname_changed",
+		Data: map[string]string{
+			"old_nickname": oldNick,
+			"new_nickname": newNick,
+		},
+	}
+}
+
+// WSNicknameAutoChanged 服务端因昵称冲突自动改名后通知该客户端
+func WSNicknameAutoChanged(nick string) WebSocketMessage {
+	return WebSocketMessage{
+		Type: "nickname_auto_changed",
+		Data: map[string]string{
+			"nickname": nick,
+		},
+	}
+}
diff --git a/server/internal/store/redis_session_store.go b/server/internal/store/redis_session_store.go
index 314f454..8e51584 100644
--- a/server/internal/store/redis_session_store.go
+++ b/server/internal/store/redis_session_store.go
@@ -9,23 +9,34 @@ import (
 	"time"
 
 	"github.com/redis/go-redis/v9"
+
+	"cancerai.top/toolbox-server/internal/pkg/hash"
 )
 
 // 包级错误，业务层可以 errors.Is 检查
 var (
-	ErrSessionNotFound = errors.New("session not found or expired")
-	ErrDuplicateJoin   = errors.New("nickname already joined this session")
-	ErrDuplicateSubmit = errors.New("this nickname has already submitted")
+	ErrSessionNotFound  = errors.New("session not found or expired")
+	ErrDuplicateJoin    = errors.New("nickname already joined this session")
+	ErrDuplicateSubmit  = errors.New("this nickname has already submitted")
+	ErrNicknameConflict = errors.New("nickname conflict (exists or matches initiator)")
+	ErrOldNotFound      = errors.New("old nickname not found in session")
 )
 
 const (
 	redisKeyPrefix   = "dualcheck:session:"
 	fieldCreatedAt   = "created_at"
 	fieldInitHash    = "initiator_hash"
+	fieldInitText    = "initiator_text" // 发起方原始文本（trim 前）
 	fieldInitNick    = "initiator_nickname"
+	fieldInitBrowser = "initiator_browser_id"
 	fieldAllowResub  = "allow_resubmit"
-	// participant:{nick} 存该参与者的哈希值；participant:{nick}:match 存 "1"/"0"
+	fieldIgnoreWs    = "ignore_ws"
+	// participant:{nick} 存该参与者的哈希值；participant:{nick}:text 存原始文本；participant:{nick}:match 存 "1"/"0"
+	// participant:{nick}:browser_id 存该参与者的 browserId
 	partFieldPrefix  = "participant:"
+	partTextSuffix   = ":text"
+	partMatchSuffix  = ":match"
+	partBrowserSuffix = ":browser_id"
 )
 
 // ── 五个 Lua 脚本 ──
@@ -37,17 +48,22 @@ if redis.call("EXISTS", key) ~= 0 then
     return 0
 end
 redis.call("HSET", key, "created_at", ARGV[1])
+redis.call("HSET", key, "initiator_nickname", ARGV[2])
+redis.call("HSET", key, "initiator_browser_id", ARGV[3])
 redis.call("HSET", key, "allow_resubmit", "0")
-redis.call("EXPIRE", key, ARGV[2])
+redis.call("HSET", key, "ignore_ws", "0")
+redis.call("EXPIRE", key, ARGV[4])
 return 1
 `)
 
 // joinParticipantLuaScript 登记参与者昵称（空哈希占位，表示已加入未提交）
 // KEYS[1] = session key
 // ARGV[1] = nickname
+// ARGV[2] = browserId
 var joinParticipantLuaScript = redis.NewScript(`
 local key = KEYS[1]
 local nick = ARGV[1]
+local bid = ARGV[2] or ""
 local exists = redis.call("EXISTS", key)
 if exists == 0 then
     return redis.error_reply("SESSION_NOT_FOUND")
@@ -58,20 +74,25 @@ if redis.call("HEXISTS", key, field) == 1 then
     return 1
 end
 redis.call("HSET", key, field, "")
+if bid ~= "" then
+    redis.call("HSET", key, field .. ":browser_id", bid)
+end
 return 1
 `)
 
 // submitParticipantLuaScript 参与者提交自己的哈希
-// 原子完成：检查 → 写入 → 与 initiator_hash 比对（若发起方已提交）
+// 原子完成：检查 → 写入哈希+原始文本 → 与 initiator_hash 比对（若发起方已提交）
 // 若已提交但 allow_resubmit=1 则覆盖（重算 match）
 // KEYS[1] = session key
 // ARGV[1] = nickname
-// ARGV[2] = hash hex
+// ARGV[2] = hash hex（已按当前 ignore_ws 规则 trim + hash）
+// ARGV[3] = 原始文本（trim 前）
 // 返回 {initiatorSubmitted (0/1), match ("1"/"0"/"")}
 var submitParticipantLuaScript = redis.NewScript(`
 local key = KEYS[1]
 local nick = ARGV[1]
 local hash_val = ARGV[2]
+local orig_text = ARGV[3]
 
 if redis.call("EXISTS", key) == 0 then
     return redis.error_reply("SESSION_NOT_FOUND")
@@ -90,8 +111,9 @@ if existing ~= "" then
     end
 end
 
--- 写入（覆盖）哈希
+-- 写入（覆盖）哈希 + 原始文本
 redis.call("HSET", key, field, hash_val)
+redis.call("HSET", key, field .. ":text", orig_text)
 -- 清除旧的 match 字段，稍后按需重算
 redis.call("HDEL", key, field .. ":match")
 
@@ -106,14 +128,16 @@ end
 `)
 
 // submitInitiatorLuaScript 发起方提交标准答案
-// 写入 initiator_hash 后，遍历所有已提交的 participant，批量计算 match
+// 写入 initiator_hash + initiator_text 后，遍历所有已提交的 participant，批量计算 match
 // KEYS[1] = session key
 // ARGV[1] = nickname
-// ARGV[2] = initiator hash
+// ARGV[2] = initiator hash（已按当前 ignore_ws 规则 trim + hash）
+// ARGV[3] = 原始文本（trim 前）
 var submitInitiatorLuaScript = redis.NewScript(`
 local key = KEYS[1]
 local nick = ARGV[1]
 local init_hash = ARGV[2]
+local orig_text = ARGV[3]
 
 if redis.call("EXISTS", key) == 0 then
     return redis.error_reply("SESSION_NOT_FOUND")
@@ -125,6 +149,7 @@ if redis.call("HEXISTS", key, "initiator_hash") == 1 then
 end
 
 redis.call("HSET", key, "initiator_hash", init_hash)
+redis.call("HSET", key, "initiator_text", orig_text)
 redis.call("HSET", key, "initiator_nickname", nick)
 
 -- 遍历所有 participant:{nick} 且哈希非空的，计算 match
@@ -134,6 +159,7 @@ for i = 1, #all, 2 do
     local val = all[i + 1]
     if string.sub(field, 1, #("participant:")) == "participant:"
        and not string.find(field, ":match$")
+       and not string.find(field, ":text$")
        and val ~= "" then
         local match = (val == init_hash) and "1" or "0"
         redis.call("HSET", key, field .. ":match", match)
@@ -142,6 +168,71 @@ end
 return 1
 `)
 
+// renameParticipantLuaScript 原子重命名参与者
+// 检查：session 存在、old 存在、new 不与 initiator_nickname/已有 participant 冲突
+// （但如果 oldNick 的 browserId 和冲突方相同，视为同一个人，跳过冲突）
+// 迁移 participant:{old}、participant:{old}:text、participant:{old}:match、participant:{old}:browser_id → new
+// KEYS[1] = session key
+// ARGV[1] = old nickname
+// ARGV[2] = new nickname
+// ARGV[3] = old participant's browserId
+var renameParticipantLuaScript = redis.NewScript(`
+local key = KEYS[1]
+local oldNick = ARGV[1]
+local newNick = ARGV[2]
+local oldBid = ARGV[3] or ""
+
+if redis.call("EXISTS", key) == 0 then
+    return redis.error_reply("SESSION_NOT_FOUND")
+end
+
+-- oldNick 必须存在
+local oldField = "participant:" .. oldNick
+if redis.call("HEXISTS", key, oldField) == 0 then
+    return redis.error_reply("OLD_NOT_FOUND")
+end
+
+-- newNick 不能等于发起方昵称（除非是同一个浏览器）
+local initNick = redis.call("HGET", key, "initiator_nickname")
+local initBid = redis.call("HGET", key, "initiator_browser_id") or ""
+if initNick and initNick == newNick then
+    if oldBid == "" or initBid ~= oldBid then
+        return redis.error_reply("NICKNAME_CONFLICT")
+    end
+end
+
+-- newNick 不能已被其他 participant 占用（除非是同一个浏览器）
+local newField = "participant:" .. newNick
+if redis.call("HEXISTS", key, newField) == 1 then
+    local newBid = redis.call("HGET", key, newField .. ":browser_id") or ""
+    if oldBid == "" or newBid ~= oldBid then
+        return redis.error_reply("NICKNAME_CONFLICT")
+    end
+end
+
+-- 迁移四个 field
+local hashVal = redis.call("HGET", key, oldField)
+local textVal = redis.call("HGET", key, oldField .. ":text")
+local matchVal = redis.call("HGET", key, oldField .. ":match")
+local bidVal = redis.call("HGET", key, oldField .. ":browser_id")
+
+redis.call("HSET", key, newField, hashVal)
+if textVal ~= false then
+    redis.call("HSET", key, newField .. ":text", textVal)
+end
+if matchVal ~= false then
+    redis.call("HSET", key, newField .. ":match", matchVal)
+end
+if bidVal ~= false then
+    redis.call("HSET", key, newField .. ":browser_id", bidVal)
+end
+redis.call("HDEL", key, oldField)
+redis.call("HDEL", key, oldField .. ":text")
+redis.call("HDEL", key, oldField .. ":match")
+redis.call("HDEL", key, oldField .. ":browser_id")
+return 1
+`)
+
 // ── RedisSessionStore 实现 ──
 
 type RedisSessionStore struct {
@@ -158,14 +249,15 @@ func key(sessionID string) string {
 }
 
 // Create 原子创建会话 Hash key
-func (s *RedisSessionStore) Create(ctx context.Context, sessionID string, ttl time.Duration) error {
+func (s *RedisSessionStore) Create(ctx context.Context, sessionID, initiatorNickname, initiatorBrowserID string, ttl time.Duration) error {
 	if ttl <= 0 {
 		ttl = s.ttl
 	}
 	now := time.Now().Unix()
 	ttlSeconds := int64(ttl.Seconds())
 
-	result, err := createLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, now, ttlSeconds).Int64()
+	result, err := createLuaScript.Run(ctx, s.rdb, []string{key(sessionID)},
+		now, initiatorNickname, initiatorBrowserID, ttlSeconds).Int64()
 	if err != nil {
 		return fmt.Errorf("redis create session: %w", err)
 	}
@@ -176,8 +268,8 @@ func (s *RedisSessionStore) Create(ctx context.Context, sessionID string, ttl ti
 }
 
 // JoinParticipant 登记参与者（空哈希占位）
-func (s *RedisSessionStore) JoinParticipant(ctx context.Context, sessionID, nickname string) error {
-	_, err := joinParticipantLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname).Int64()
+func (s *RedisSessionStore) JoinParticipant(ctx context.Context, sessionID, nickname, browserID string) error {
+	_, err := joinParticipantLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname, browserID).Int64()
 	if err != nil {
 		msg := err.Error()
 		if strings.Contains(msg, "SESSION_NOT_FOUND") {
@@ -188,9 +280,9 @@ func (s *RedisSessionStore) JoinParticipant(ctx context.Context, sessionID, nick
 	return nil
 }
 
-// SubmitParticipant 参与者提交自己的文本哈希
-func (s *RedisSessionStore) SubmitParticipant(ctx context.Context, sessionID, nickname, hashHex string) (bool, *bool, error) {
-	result, err := submitParticipantLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname, hashHex).Result()
+// SubmitParticipant 参与者提交自己的文本哈希（同时存原始文本）
+func (s *RedisSessionStore) SubmitParticipant(ctx context.Context, sessionID, nickname, hashHex, originalText string) (bool, *bool, error) {
+	result, err := submitParticipantLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname, hashHex, originalText).Result()
 	if err != nil {
 		msg := err.Error()
 		switch {
@@ -200,10 +292,10 @@ func (s *RedisSessionStore) SubmitParticipant(ctx context.Context, sessionID, ni
 			return false, nil, ErrDuplicateSubmit
 		case strings.Contains(msg, "NICKNAME_NOT_JOINED"):
 			// 参与者没走 join 直接 submit，自动补登记
-			if err := s.JoinParticipant(ctx, sessionID, nickname); err != nil {
+			if err := s.JoinParticipant(ctx, sessionID, nickname, ""); err != nil {
 				return false, nil, err
 			}
-			return s.SubmitParticipant(ctx, sessionID, nickname, hashHex)
+			return s.SubmitParticipant(ctx, sessionID, nickname, hashHex, originalText)
 		default:
 			return false, nil, fmt.Errorf("redis submit participant: %w", err)
 		}
@@ -219,9 +311,9 @@ func (s *RedisSessionStore) SubmitParticipant(ctx context.Context, sessionID, ni
 	return initSubmitted, match, nil
 }
 
-// SubmitInitiator 发起方提交标准答案哈希
-func (s *RedisSessionStore) SubmitInitiator(ctx context.Context, sessionID, nickname, hashHex string) error {
-	_, err := submitInitiatorLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname, hashHex).Int64()
+// SubmitInitiator 发起方提交标准答案哈希（同时存原始文本）
+func (s *RedisSessionStore) SubmitInitiator(ctx context.Context, sessionID, nickname, hashHex, originalText string) error {
+	_, err := submitInitiatorLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, nickname, hashHex, originalText).Int64()
 	if err != nil {
 		if strings.Contains(err.Error(), "SESSION_NOT_FOUND") {
 			return ErrSessionNotFound
@@ -248,6 +340,134 @@ func (s *RedisSessionStore) SetResubmit(ctx context.Context, sessionID string, a
 	return s.rdb.HSet(ctx, key, fieldAllowResub, val).Err()
 }
 
+func (s *RedisSessionStore) SetIgnoreWs(ctx context.Context, sessionID string, ignore bool) error {
+	key := key(sessionID)
+	exists, err := s.rdb.Exists(ctx, key).Result()
+	if err != nil {
+		return fmt.Errorf("redis exists: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+	val := "0"
+	if ignore {
+		val = "1"
+	}
+	return s.rdb.HSet(ctx, key, fieldIgnoreWs, val).Err()
+}
+
+func (s *RedisSessionStore) GetIgnoreWs(ctx context.Context, sessionID string) (bool, error) {
+	v, err := s.rdb.HGet(ctx, key(sessionID), fieldIgnoreWs).Result()
+	if err != nil {
+		if err == redis.Nil {
+			return false, nil
+		}
+		return false, fmt.Errorf("redis hget ignore_ws: %w", err)
+	}
+	return v == "1", nil
+}
+
+// RecalcMatches 按新的 ignoreWs 规则重新 trim + hash 所有已提交文本并重算 match
+func (s *RedisSessionStore) RecalcMatches(ctx context.Context, sessionID string, ignoreWs bool) error {
+	k := key(sessionID)
+	all, err := s.rdb.HGetAll(ctx, k).Result()
+	if err != nil {
+		return fmt.Errorf("redis hgetall: %w", err)
+	}
+	if len(all) == 0 {
+		return ErrSessionNotFound
+	}
+
+	// 读发起方原始文本
+	initText := all[fieldInitText]
+	if initText == "" {
+		return nil // 发起方还没提交，不需要重算
+	}
+	initProcessed := initText
+	if ignoreWs {
+		initProcessed = strings.TrimSpace(initText)
+	}
+	initHash := hash.SHA256(initProcessed)
+
+	pipe := s.rdb.TxPipeline()
+	pipe.HSet(ctx, k, fieldInitHash, initHash)
+
+	// 遍历所有已提交参与者，重算 hash + match
+	for field, val := range all {
+		if !strings.HasPrefix(field, partFieldPrefix) {
+			continue
+		}
+		if strings.HasSuffix(field, partMatchSuffix) || strings.HasSuffix(field, partTextSuffix) {
+			continue
+		}
+		if val == "" {
+			continue
+		}
+		textField := field + partTextSuffix
+		origText := all[textField]
+		if origText == "" {
+			continue // 旧数据（没存过原始文本），跳过
+		}
+		processed := origText
+		if ignoreWs {
+			processed = strings.TrimSpace(origText)
+		}
+		newHash := hash.SHA256(processed)
+		match := "0"
+		if newHash == initHash {
+			match = "1"
+		}
+		pipe.HSet(ctx, k, field, newHash)
+		pipe.HSet(ctx, k, field+partMatchSuffix, match)
+	}
+
+	_, err = pipe.Exec(ctx)
+	if err != nil {
+		return fmt.Errorf("redis recalc pipeline: %w", err)
+	}
+	return nil
+}
+
+// UpdateParticipantNickname 原子重命名参与者
+func (s *RedisSessionStore) UpdateParticipantNickname(ctx context.Context, sessionID, oldNick, newNick, oldBrowserID string) error {
+	_, err := renameParticipantLuaScript.Run(ctx, s.rdb, []string{key(sessionID)}, oldNick, newNick, oldBrowserID).Int64()
+	if err != nil {
+		msg := err.Error()
+		switch {
+		case strings.Contains(msg, "SESSION_NOT_FOUND"):
+			return ErrSessionNotFound
+		case strings.Contains(msg, "OLD_NOT_FOUND"):
+			return ErrOldNotFound
+		case strings.Contains(msg, "NICKNAME_CONFLICT"):
+			return ErrNicknameConflict
+		default:
+			return fmt.Errorf("redis rename participant: %w", err)
+		}
+	}
+	return nil
+}
+
+// RemoveParticipant 参与者离开时从 Redis 删除其所有字段
+func (s *RedisSessionStore) RemoveParticipant(ctx context.Context, sessionID, nickname string) error {
+	k := key(sessionID)
+	exists, err := s.rdb.Exists(ctx, k).Result()
+	if err != nil {
+		return fmt.Errorf("redis exists: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+	pipe := s.rdb.TxPipeline()
+	pipe.HDel(ctx, k, partFieldPrefix+nickname)
+	pipe.HDel(ctx, k, partFieldPrefix+nickname+partTextSuffix)
+	pipe.HDel(ctx, k, partFieldPrefix+nickname+partMatchSuffix)
+	_, err = pipe.Exec(ctx)
+	if err != nil {
+		return fmt.Errorf("redis remove participant: %w", err)
+	}
+	return nil
+}
+
 // Get 获取会话当前状态全量快照
 func (s *RedisSessionStore) Get(ctx context.Context, sessionID string) (*SessionSnapshot, error) {
 	exists, err := s.rdb.Exists(ctx, key(sessionID)).Result()
@@ -272,8 +492,10 @@ func (s *RedisSessionStore) Get(ctx context.Context, sessionID string) (*Session
 		SessionID:          sessionID,
 		InitiatorHash:      hash[fieldInitHash],
 		InitiatorNickname:  hash[fieldInitNick],
+		InitiatorBrowserID: hash[fieldInitBrowser],
 		InitiatorSubmitted: hash[fieldInitHash] != "",
 		AllowResubmit:      hash[fieldAllowResub] == "1",
+		IgnoreWs:           hash[fieldIgnoreWs] == "1",
 		ExpiresAt:          time.Now().Add(ttl),
 	}
 
@@ -281,7 +503,10 @@ func (s *RedisSessionStore) Get(ctx context.Context, sessionID string) (*Session
 	var nicks []string
 	partMap := map[string]string{} // nick → hash
 	for k, v := range hash {
-		if strings.HasPrefix(k, partFieldPrefix) && !strings.HasSuffix(k, ":match") {
+		if strings.HasPrefix(k, partFieldPrefix) &&
+			!strings.HasSuffix(k, partMatchSuffix) &&
+			!strings.HasSuffix(k, partTextSuffix) &&
+			!strings.HasSuffix(k, partBrowserSuffix) {
 			nick := strings.TrimPrefix(k, partFieldPrefix)
 			nicks = append(nicks, nick)
 			partMap[nick] = v
@@ -294,6 +519,7 @@ func (s *RedisSessionStore) Get(ctx context.Context, sessionID string) (*Session
 		h := partMap[nick]
 		p := ParticipantInfo{
 			Nickname:  nick,
+			BrowserID: hash[partFieldPrefix+nick+partBrowserSuffix],
 			Submitted: h != "",
 		}
 		if h != "" && initiatorHash != "" {
diff --git a/server/internal/store/session_store.go b/server/internal/store/session_store.go
index 5e93e90..bbcdd55 100644
--- a/server/internal/store/session_store.go
+++ b/server/internal/store/session_store.go
@@ -17,6 +17,7 @@ type Session struct {
 // ParticipantInfo 参与者在全量快照中的状态
 type ParticipantInfo struct {
 	Nickname  string `json:"nickname"`
+	BrowserID string `json:"browser_id,omitempty"`
 	Submitted bool   `json:"submitted"`
 	Match     *bool  `json:"match,omitempty"`
 }
@@ -26,33 +27,52 @@ type SessionSnapshot struct {
 	SessionID          string            `json:"session_id"`
 	InitiatorHash      string            `json:"-"` // 发起方标准答案哈希，不对外暴露
 	InitiatorNickname  string            `json:"initiator_nickname"`
+	InitiatorBrowserID string            `json:"initiator_browser_id,omitempty"`
 	InitiatorSubmitted bool              `json:"initiator_submitted"`
 	AllowResubmit      bool              `json:"allow_resubmit"`
+	IgnoreWs           bool              `json:"ignore_ws"` // 是否忽略首尾空白
 	Participants       []ParticipantInfo `json:"participants"`
 	ExpiresAt          time.Time         `json:"expires_at"`
 }
 
 // SessionStore 会话存储接口
 type SessionStore interface {
-	// Create 原子创建会话（SET NX EX）
-	Create(ctx context.Context, id string, ttl time.Duration) error
+	// Create 原子创建会话（SET NX EX），同时记录发起方昵称和 browserId
+	Create(ctx context.Context, id, initiatorNickname, initiatorBrowserID string, ttl time.Duration) error
 
-	// SubmitInitiator 发起方提交标准答案（initiator_hash + initiator_nickname）
+	// SubmitInitiator 发起方提交标准答案（initiator_hash + initiator_nickname + 原始文本）
 	// 同时立即为所有已提交的参与者计算 match
-	SubmitInitiator(ctx context.Context, sessionID, nickname, hashHex string) error
+	SubmitInitiator(ctx context.Context, sessionID, nickname, hashHex, originalText string) error
 
-	// SubmitParticipant 参与者提交自己的文本（按 nickname 唯一标识）
+	// SubmitParticipant 参与者提交自己的文本（按 nickname 唯一标识，同时存原始文本）
 	// 返回：initiatorSubmitted（发起方是否已提交，是则 match 已算出）、match
-	SubmitParticipant(ctx context.Context, sessionID, nickname, hashHex string) (
+	SubmitParticipant(ctx context.Context, sessionID, nickname, hashHex, originalText string) (
 		initiatorSubmitted bool, match *bool, err error)
 
 	// JoinParticipant 参与者加入会话（只登记昵称，不提交文本）
-	// 用于 WS 连接时实时广播 joined 事件
-	JoinParticipant(ctx context.Context, sessionID, nickname string) error
+	// browserId 用于识别"同一个人"，避免跨 tab 昵称冲突
+	JoinParticipant(ctx context.Context, sessionID, nickname, browserID string) error
 
 	// SetResubmit 设置是否允许参与者重复提交
 	SetResubmit(ctx context.Context, sessionID string, allow bool) error
 
+	// SetIgnoreWs 设置比对时是否忽略首尾空白（1=忽略，0=不忽略）
+	SetIgnoreWs(ctx context.Context, sessionID string, ignore bool) error
+
+	// GetIgnoreWs 获取当前会话的 ignore_ws 设置
+	GetIgnoreWs(ctx context.Context, sessionID string) (bool, error)
+
+	// RecalcMatches 按新的 ignoreWs 规则重新 trim + hash 所有已提交文本并重算 match
+	RecalcMatches(ctx context.Context, sessionID string, ignoreWs bool) error
+
+	// UpdateParticipantNickname 原子重命名参与者：将 participant:{old} → participant:{new}
+	// oldBrowserID 用于判断是否与冲突方是同一个浏览器（跳过冲突）
+	// 返回业务错误：ErrSessionNotFound / ErrNicknameConflict
+	UpdateParticipantNickname(ctx context.Context, sessionID, oldNick, newNick, oldBrowserID string) error
+
+	// RemoveParticipant 参与者离开时从 Redis 删除其所有字段（hash/text/match）
+	RemoveParticipant(ctx context.Context, sessionID, nickname string) error
+
 	// Get 获取会话当前状态全量快照
 	Get(ctx context.Context, sessionID string) (*SessionSnapshot, error)
 
diff --git a/server/internal/tools/dual_check/handler.go b/server/internal/tools/dual_check/handler.go
index a8b0b85..7bc84a8 100644
--- a/server/internal/tools/dual_check/handler.go
+++ b/server/internal/tools/dual_check/handler.go
@@ -3,6 +3,7 @@ package dual_check
 import (
 	"errors"
 	"net/http"
+	"strings"
 	"unicode/utf8"
 
 	pkgws "cancerai.top/toolbox-server/internal/pkg/websocket"
@@ -38,7 +39,11 @@ func (h *Handler) Create(c *gin.Context) {
 		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
 		return
 	}
-	resp, err := h.service.CreateSession(c.Request.Context(), req.Nickname)
+	if err := validateNickname(req.Nickname); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+	resp, err := h.service.CreateSession(c.Request.Context(), req.Nickname, req.BrowserID)
 	if err != nil {
 		var be *BusinessError
 		if errors.As(err, &be) {
@@ -64,6 +69,10 @@ func (h *Handler) Submit(c *gin.Context) {
 		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
 		return
 	}
+	if err := validateNickname(req.Nickname); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
 	if utf8.RuneCountInString(req.Text) > h.maxLen {
 		response.BadRequest(c, "text too long")
 		return
@@ -82,37 +91,33 @@ func (h *Handler) Submit(c *gin.Context) {
 		return
 	}
 
-	// 广播事件到房间内所有连接（包括发起方和其他参与者）
+	// 广播事件到房间内所有连接
 	switch req.Role {
 	case "initiator":
-		// 发起方刚提交：触发全量快照推送（所有参与者都需要更新）
 		sess, _ := h.service.GetSession(c.Request.Context(), req.SessionID)
 		if sess != nil {
 			h.hub.Broadcast(req.SessionID, response.WSFullState(sess))
 		}
 	case "participant":
-		// 参与者刚提交：推送 participant_submitted 事件
-		// 发起方需要更新该参与者的提交状态 + 可能的 match 结果
 		h.hub.Broadcast(req.SessionID, response.WSParticipantSubmitted(req.Nickname, resp))
 	}
 
 	response.Success(c, resp)
 }
 
-// Join POST /api/v1/dual-check/join — 参与者加入（登记昵称）
+// Join POST /api/v1/dual-check/join
 func (h *Handler) Join(c *gin.Context) {
 	var req JoinRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
 		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
 		return
 	}
-	sessionID := c.Param("session_id")
-	if sessionID == "" {
-		response.BadRequest(c, "session_id is required")
+	if err := validateNickname(req.Nickname); err != nil {
+		response.BadRequest(c, err.Error())
 		return
 	}
 
-	sess, err := h.service.JoinParticipant(c.Request.Context(), sessionID, req.Nickname)
+	sess, actualNick, err := h.service.JoinParticipant(c.Request.Context(), req.SessionID, req.Nickname, req.BrowserID)
 	if err != nil {
 		var be *BusinessError
 		if errors.As(err, &be) {
@@ -124,16 +129,27 @@ func (h *Handler) Join(c *gin.Context) {
 		return
 	}
 
-	// 广播 participant_joined 事件
-	h.hub.Broadcast(sessionID, response.WSParticipantJoined(req.Nickname))
+	h.hub.Broadcast(req.SessionID, response.WSParticipantJoined(actualNick))
 
+	if actualNick != req.Nickname {
+		response.Success(c, gin.H{
+			"session":         sess,
+			"actual_nickname": actualNick,
+			"renamed":         true,
+		})
+		return
+	}
 	response.Success(c, sess)
 }
 
-// GetSession GET /api/v1/dual-check/session/:session_id
+// GetSession POST /api/v1/dual-check/session
 func (h *Handler) GetSession(c *gin.Context) {
-	sessionID := c.Param("session_id")
-	sess, err := h.service.GetSession(c.Request.Context(), sessionID)
+	var req SessionRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
+		return
+	}
+	sess, err := h.service.GetSession(c.Request.Context(), req.SessionID)
 	if err != nil {
 		var be *BusinessError
 		if errors.As(err, &be) && be.Code == ErrCodeSessionNotFound {
@@ -146,11 +162,14 @@ func (h *Handler) GetSession(c *gin.Context) {
 	response.Success(c, sess)
 }
 
-// CheckSession GET /api/v1/dual-check/check/:session_id
-// 前端加入前预校验
+// CheckSession POST /api/v1/dual-check/check
 func (h *Handler) CheckSession(c *gin.Context) {
-	sessionID := c.Param("session_id")
-	info, err := h.service.CheckSession(c.Request.Context(), sessionID)
+	var req SessionRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
+		return
+	}
+	info, err := h.service.CheckSession(c.Request.Context(), req.SessionID)
 	if err != nil {
 		response.InternalError(c, "check session failed")
 		return
@@ -162,21 +181,15 @@ func (h *Handler) CheckSession(c *gin.Context) {
 	response.Success(c, info)
 }
 
-// SetResubmit POST /api/v1/dual-check/session/:session_id/resubmit
-// 发起方切换"允许参与者重新提交"开关
+// SetResubmit POST /api/v1/dual-check/resubmit
 func (h *Handler) SetResubmit(c *gin.Context) {
-	sessionID := c.Param("session_id")
-	if sessionID == "" {
-		response.BadRequest(c, "session_id is required")
-		return
-	}
 	var req SetResubmitRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
 		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
 		return
 	}
 
-	sess, err := h.service.SetResubmit(c.Request.Context(), sessionID, req.Allow)
+	sess, err := h.service.SetResubmit(c.Request.Context(), req.SessionID, req.Allow)
 	if err != nil {
 		var be *BusinessError
 		if errors.As(err, &be) {
@@ -188,26 +201,49 @@ func (h *Handler) SetResubmit(c *gin.Context) {
 		return
 	}
 
-	// 广播开关变化给所有参与者
-	h.hub.Broadcast(sessionID, response.WSResubmitChanged(req.Allow))
+	h.hub.Broadcast(req.SessionID, response.WSResubmitChanged(req.Allow))
 
 	response.Success(c, sess)
 }
 
-// EndSession POST /api/v1/dual-check/session/:session_id/end
-// 发起方主动结束会话：先广播 session_ended，再 Delete Redis key
+// SetIgnoreWs POST /api/v1/dual-check/ignore-ws
+func (h *Handler) SetIgnoreWs(c *gin.Context) {
+	var req SetIgnoreWsRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
+		return
+	}
+
+	sess, err := h.service.SetIgnoreWs(c.Request.Context(), req.SessionID, req.Ignore)
+	if err != nil {
+		var be *BusinessError
+		if errors.As(err, &be) {
+			response.Fail(c, be.Code, be.Error())
+			return
+		}
+		h.logger.Error("set ignore_ws error", zap.Error(err))
+		response.InternalError(c, "set ignore_ws failed")
+		return
+	}
+
+	h.hub.Broadcast(req.SessionID, response.WSIgnoreWsChanged(req.Ignore))
+
+	response.Success(c, sess)
+}
+
+// EndSession POST /api/v1/dual-check/end
 func (h *Handler) EndSession(c *gin.Context) {
-	sessionID := c.Param("session_id")
-	if sessionID == "" {
-		response.BadRequest(c, "session_id is required")
+	var req SessionRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, ErrMessage(ErrCodeInvalidParam))
 		return
 	}
 
 	// 先广播，让所有参与方 UI 都弹提示
-	h.hub.Broadcast(sessionID, response.WSSessionEnded())
+	h.hub.Broadcast(req.SessionID, response.WSSessionEnded())
 
 	// 再删除数据
-	if err := h.service.EndSession(c.Request.Context(), sessionID); err != nil {
+	if err := h.service.EndSession(c.Request.Context(), req.SessionID); err != nil {
 		h.logger.Error("end session error", zap.Error(err))
 		response.InternalError(c, "end session failed")
 		return
@@ -216,5 +252,16 @@ func (h *Handler) EndSession(c *gin.Context) {
 	response.Success(c, gin.H{"ended": true})
 }
 
-// 占位，避免 http.StatusOK 未使用
+// validateNickname 统一的昵称校验：字符数 1-32（按 Unicode rune）
+func validateNickname(n string) error {
+	n = strings.TrimSpace(n)
+	if utf8.RuneCountInString(n) == 0 {
+		return errors.New("nickname is required")
+	}
+	if utf8.RuneCountInString(n) > 32 {
+		return errors.New("nickname must be 1-32 characters")
+	}
+	return nil
+}
+
 var _ = http.StatusOK
diff --git a/server/internal/tools/dual_check/model.go b/server/internal/tools/dual_check/model.go
index 364225b..8ddf4c7 100644
--- a/server/internal/tools/dual_check/model.go
+++ b/server/internal/tools/dual_check/model.go
@@ -8,7 +8,8 @@ import "time"
 // ── 创建会话 ──
 
 type CreateRequest struct {
-	Nickname string `json:"nickname" binding:"required,min=1,max=32"`
+	Nickname  string `json:"nickname" binding:"required,min=1"`
+	BrowserID string `json:"browser_id"`
 }
 
 // CreateResponse 创建成功
@@ -23,7 +24,7 @@ type CreateResponse struct {
 
 type SubmitRequest struct {
 	SessionID string `json:"session_id" binding:"required,min=8,max=64"`
-	Nickname  string `json:"nickname"  binding:"required,min=1,max=32"`
+	Nickname  string `json:"nickname"  binding:"required,min=1"`
 	Role      string `json:"role"      binding:"required,oneof=initiator participant"`
 	Text      string `json:"text"      binding:"required"`
 }
@@ -38,7 +39,9 @@ type SubmitResponse struct {
 // ── 参与者加入 ──
 
 type JoinRequest struct {
-	Nickname string `json:"nickname" binding:"required,min=1,max=32"`
+	SessionID string `json:"session_id" binding:"required,min=8,max=64"`
+	Nickname  string `json:"nickname"  binding:"required,min=1"`
+	BrowserID string `json:"browser_id"`
 }
 
 // JoinResponse 返回当前会话全量状态，供参与者初始化 UI
@@ -50,12 +53,18 @@ type JoinResponse struct {
 
 // ── 会话全量状态（发起方拉取 / 发起方 WS 初始化） ──
 
+// SessionRequest 统一的 session_id 请求体
+type SessionRequest struct {
+	SessionID string `json:"session_id" binding:"required,min=8,max=64"`
+}
+
 // SessionResponse 发起方看到的会话状态（完整参与者列表）
 type SessionResponse struct {
 	SessionID          string            `json:"session_id"`
 	InitiatorNickname  string            `json:"initiator_nickname"`
 	InitiatorReady     bool              `json:"initiator_ready"`
 	AllowResubmit      bool              `json:"allow_resubmit"`
+	IgnoreWs           bool              `json:"ignore_ws"`
 	Participants       []ParticipantResp `json:"participants"`
 	TTLSeconds         int64             `json:"ttl_seconds"`
 }
@@ -74,6 +83,7 @@ type CheckResponse struct {
 	Exists            bool   `json:"exists"`
 	InitiatorReady    bool   `json:"initiator_ready"`
 	AllowResubmit     bool   `json:"allow_resubmit"`
+	IgnoreWs          bool   `json:"ignore_ws"`
 	ParticipantCount  int    `json:"participant_count"`
 	TTLSeconds        int64  `json:"ttl_seconds"`
 }
@@ -82,5 +92,12 @@ type CheckResponse struct {
 
 // SetResubmitRequest 发起方切换"允许参与者重新提交"开关
 type SetResubmitRequest struct {
-	Allow bool `json:"allow"`
+	SessionID string `json:"session_id" binding:"required,min=8,max=64"`
+	Allow     bool   `json:"allow"`
+}
+
+// SetIgnoreWsRequest 发起方切换"忽略首尾空白"开关
+type SetIgnoreWsRequest struct {
+	SessionID string `json:"session_id" binding:"required,min=8,max=64"`
+	Ignore    bool   `json:"ignore"`
 }
diff --git a/server/internal/tools/dual_check/routes.go b/server/internal/tools/dual_check/routes.go
index 3f04484..8eb4a99 100644
--- a/server/internal/tools/dual_check/routes.go
+++ b/server/internal/tools/dual_check/routes.go
@@ -25,14 +25,15 @@ func Register(
 	h := NewHandler(svc, hub, logger, maxTextLen)
 	ws := NewWSHandler(svc, hub, logger)
 
-	// REST API
-	group.POST("/create", h.Create)                          // 发起方创建会话
-	group.POST("/submit", h.Submit)                          // 发起方或参与者提交文本
-	group.POST("/session/:session_id/join", h.Join)          // 参与者加入（登记昵称）
-	group.POST("/session/:session_id/resubmit", h.SetResubmit) // 发起方切换"允许重提交"开关
-	group.POST("/session/:session_id/end", h.EndSession)     // 发起方主动结束会话
-	group.GET("/session/:session_id", h.GetSession)          // 拉全量状态
-	group.GET("/check/:session_id", h.CheckSession)          // 加入前预校验
+	// REST API — 所有 session_id 走 POST body
+	group.POST("/create", h.Create)            // 发起方创建会话
+	group.POST("/submit", h.Submit)            // 发起方或参与者提交文本
+	group.POST("/join", h.Join)                // 参与者加入（登记昵称）
+	group.POST("/resubmit", h.SetResubmit)     // 发起方切换"允许重提交"开关
+	group.POST("/ignore-ws", h.SetIgnoreWs)    // 发起方切换"忽略首尾空白"开关
+	group.POST("/end", h.EndSession)           // 发起方主动结束会话
+	group.POST("/session", h.GetSession)       // 拉全量状态
+	group.POST("/check", h.CheckSession)       // 加入前预校验
 
 	// WebSocket 实时推送（带 role + nickname 查询参数）
 	group.GET("/ws", ws.Handle)
diff --git a/server/internal/tools/dual_check/service.go b/server/internal/tools/dual_check/service.go
index d0f96de..6e678fd 100644
--- a/server/internal/tools/dual_check/service.go
+++ b/server/internal/tools/dual_check/service.go
@@ -2,9 +2,13 @@ package dual_check
 
 import (
 	"context"
+	"crypto/rand"
 	"errors"
 	"fmt"
+	"math/big"
+	"strings"
 	"time"
+	"unicode/utf8"
 
 	"cancerai.top/toolbox-server/internal/pkg/hash"
 	"cancerai.top/toolbox-server/internal/pkg/sessionid"
@@ -32,13 +36,13 @@ func NewService(s store.SessionStore, logger *zap.Logger, ttl time.Duration) *Se
 
 // ── Create ──
 
-func (s *Service) CreateSession(ctx context.Context, nickname string) (*CreateResponse, error) {
+func (s *Service) CreateSession(ctx context.Context, nickname, browserID string) (*CreateResponse, error) {
 	var sid string
 	var err error
 	for i := 0; i < 3; i++ {
 		sid, err = sessionid.Generate()
 		if err == nil {
-			err = s.store.Create(ctx, sid, s.ttl)
+			err = s.store.Create(ctx, sid, nickname, browserID, s.ttl)
 			if err == nil {
 				break
 			}
@@ -59,28 +63,43 @@ func (s *Service) CreateSession(ctx context.Context, nickname string) (*CreateRe
 		SessionID: sid,
 		Nickname:  nickname,
 		ExpiresAt: expiresAt,
-		TTL:       int(s.ttl.Seconds()),
+		// -1 表示"由发起方在线决定生命周期"，Redis TTL 只是兜底
+		TTL: -1,
 	}, nil
 }
 
 // ── Submit（发起方 or 参与方） ──
 
 func (s *Service) Submit(ctx context.Context, req *SubmitRequest) (*SubmitResponse, error) {
-	hashHex := hash.SHA256(req.Text)
+	// 读 ignore_ws 设置，如果开启则 trim 首尾空白再 hash
+	ignoreWs, err := s.store.GetIgnoreWs(ctx, req.SessionID)
+	if err != nil {
+		if !errors.Is(err, store.ErrSessionNotFound) {
+			s.logger.Warn("GetIgnoreWs failed, defaulting to false", zap.Error(err))
+		}
+		ignoreWs = false
+	}
+	originalText := req.Text // 保存原始文本（trim 前），用于未来切换 ignore_ws 时重算
+	text := req.Text
+	if ignoreWs {
+		text = strings.TrimSpace(text)
+	}
+
+	hashHex := hash.SHA256(text)
 	req.Text = "" // 显式释放明文引用
 
 	switch req.Role {
 	case "initiator":
-		return s.submitInitiator(ctx, req.SessionID, req.Nickname, hashHex)
+		return s.submitInitiator(ctx, req.SessionID, req.Nickname, hashHex, originalText)
 	case "participant":
-		return s.submitParticipant(ctx, req.SessionID, req.Nickname, hashHex)
+		return s.submitParticipant(ctx, req.SessionID, req.Nickname, hashHex, originalText)
 	default:
 		return nil, &BusinessError{Code: ErrCodeInvalidRole}
 	}
 }
 
-func (s *Service) submitInitiator(ctx context.Context, sessionID, nickname, hashHex string) (*SubmitResponse, error) {
-	if err := s.store.SubmitInitiator(ctx, sessionID, nickname, hashHex); err != nil {
+func (s *Service) submitInitiator(ctx context.Context, sessionID, nickname, hashHex, originalText string) (*SubmitResponse, error) {
+	if err := s.store.SubmitInitiator(ctx, sessionID, nickname, hashHex, originalText); err != nil {
 		if errors.Is(err, store.ErrSessionNotFound) {
 			return nil, ErrSessionNotFound
 		}
@@ -95,8 +114,8 @@ func (s *Service) submitInitiator(ctx context.Context, sessionID, nickname, hash
 	return &SubmitResponse{Submitted: true, InitiatorReady: true}, nil
 }
 
-func (s *Service) submitParticipant(ctx context.Context, sessionID, nickname, hashHex string) (*SubmitResponse, error) {
-	initReady, match, err := s.store.SubmitParticipant(ctx, sessionID, nickname, hashHex)
+func (s *Service) submitParticipant(ctx context.Context, sessionID, nickname, hashHex, originalText string) (*SubmitResponse, error) {
+	initReady, match, err := s.store.SubmitParticipant(ctx, sessionID, nickname, hashHex, originalText)
 	if err != nil {
 		switch {
 		case errors.Is(err, store.ErrSessionNotFound):
@@ -126,28 +145,111 @@ func (s *Service) submitParticipant(ctx context.Context, sessionID, nickname, ha
 
 // ── Join ──
 
-func (s *Service) JoinParticipant(ctx context.Context, sessionID, nickname string) (*SessionResponse, error) {
-	// 检查昵称是否等于发起方昵称（不允许用发起方的昵称作为参与者）
+// JoinParticipant 参与者加入会话，自动解决昵称冲突
+// 返回 (sess, actualNick, err) — actualNick 是实际登记的昵称（可能是自动改名后的）
+func (s *Service) JoinParticipant(ctx context.Context, sessionID, nickname, participantBrowserID string) (*SessionResponse, string, error) {
 	snap, err := s.store.Get(ctx, sessionID)
 	if err != nil {
 		if errors.Is(err, store.ErrSessionNotFound) {
-			return nil, ErrSessionNotFound
+			return nil, "", ErrSessionNotFound
 		}
-		return nil, err
-	}
-	if snap.InitiatorNickname != "" && snap.InitiatorNickname == nickname {
-		return nil, &BusinessError{Code: ErrCodeNicknameExists}
+		return nil, "", err
 	}
 
-	if err := s.store.JoinParticipant(ctx, sessionID, nickname); err != nil {
+	actualNick := nickname
+	// 检查冲突：发起方昵称 或 已有参与者昵称
+	// 但如果"冲突方"的 browserId 和参与者相同（同一个浏览器的不同 tab），视为同一个人不冲突
+	if isNicknameTaken(snap, nickname, participantBrowserID) {
+		actualNick = generateSafeNickname(nickname, snap, 5, participantBrowserID)
+		s.logger.Info("nickname auto-renamed on join",
+			zap.String("session_id", truncateSessionID(sessionID)),
+			zap.String("original", nickname),
+			zap.String("actual", actualNick),
+			zap.String("browser_id", participantBrowserID))
+	}
+
+	if err := s.store.JoinParticipant(ctx, sessionID, actualNick, participantBrowserID); err != nil {
 		if errors.Is(err, store.ErrSessionNotFound) {
-			return nil, ErrSessionNotFound
+			return nil, "", ErrSessionNotFound
 		}
-		return nil, err
+		return nil, "", err
 	}
 
-	// 返回加入后的最新状态
-	return s.GetSession(ctx, sessionID)
+	sess, err := s.GetSession(ctx, sessionID)
+	return sess, actualNick, err
+}
+
+// isNicknameTaken 检查昵称是否被发起方或已有参与者占用
+// participantBrowserID：正在加入的人的 browserId——如果"冲突方"的 browserId 和他相同，视为同一个人，不冲突
+func isNicknameTaken(snap *store.SessionSnapshot, nickname, participantBrowserID string) bool {
+	if snap.InitiatorNickname != "" && snap.InitiatorNickname == nickname {
+		// 发起方和参与者是同一个浏览器 → 同一个人 → 不冲突
+		if snap.InitiatorBrowserID != "" && snap.InitiatorBrowserID == participantBrowserID {
+			return false
+		}
+		return true
+	}
+	for _, p := range snap.Participants {
+		if p.Nickname == nickname {
+			// 已有参与者和新参与者是同一个浏览器 → 同一个人 → 不冲突
+			if p.BrowserID != "" && p.BrowserID == participantBrowserID {
+				return false
+			}
+			return true
+		}
+	}
+	return false
+}
+
+// generateSafeNickname 生成不冲突的新昵称：原名-XXX（XXX 是 3 位随机数字）
+// 如果原名太长，截断后再加 -XXX，保证总长不超过 32 字符
+func generateSafeNickname(original string, snap *store.SessionSnapshot, maxRetries int, participantBrowserID string) string {
+	const suffixLen = 4 // "-" + 3 digits
+	const maxRunes = 32
+
+	// 算 base（加上 suffix 后不超过 32 runes）
+	origRunes := utf8.RuneCountInString(original)
+	var base string
+	if origRunes+suffixLen <= maxRunes {
+		base = original
+	} else {
+		// 截断到 maxRunes - suffixLen 个 rune
+		runes := []rune(original)
+		base = string(runes[:maxRunes-suffixLen])
+	}
+
+	for i := 0; i < maxRetries; i++ {
+		suffix := randomDigits(3)
+		candidate := base + "-" + suffix
+		if !isNicknameTaken(snap, candidate, participantBrowserID) {
+			return candidate
+		}
+	}
+	// 极端情况还冲突，再多加一位
+	for i := 0; i < maxRetries; i++ {
+		suffix := randomDigits(4)
+		candidate := base + "-" + suffix
+		if !isNicknameTaken(snap, candidate, participantBrowserID) {
+			return candidate
+		}
+	}
+	return base + "-" + randomDigits(3) // 兜底
+}
+
+// randomDigits 返回 n 位随机数字字符串（crypto/rand 安全）
+func randomDigits(n int) string {
+	const digits = "0123456789"
+	b := make([]byte, n)
+	for i := 0; i < n; i++ {
+		idx, err := rand.Int(rand.Reader, big.NewInt(10))
+		if err != nil {
+			// 兜底用伪随机
+			b[i] = digits[time.Now().UnixNano()%10]
+		} else {
+			b[i] = digits[idx.Int64()]
+		}
+	}
+	return string(b)
 }
 
 // ── GetSession 返回全量状态 ──
@@ -160,7 +262,6 @@ func (s *Service) GetSession(ctx context.Context, sessionID string) (*SessionRes
 		}
 		return nil, err
 	}
-	ttl := time.Until(snap.ExpiresAt)
 	parts := make([]ParticipantResp, 0, len(snap.Participants))
 	for _, p := range snap.Participants {
 		parts = append(parts, ParticipantResp{
@@ -175,8 +276,10 @@ func (s *Service) GetSession(ctx context.Context, sessionID string) (*SessionRes
 		InitiatorNickname: snap.InitiatorNickname,
 		InitiatorReady:    snap.InitiatorSubmitted,
 		AllowResubmit:     snap.AllowResubmit,
+		IgnoreWs:          snap.IgnoreWs,
 		Participants:      parts,
-		TTLSeconds:        int64(ttl.Seconds()),
+		// -1 表示会话由发起方在线决定生命周期
+		TTLSeconds:        -1,
 	}, nil
 }
 
@@ -190,16 +293,14 @@ func (s *Service) CheckSession(ctx context.Context, sessionID string) (*CheckRes
 		}
 		return nil, err
 	}
-	ttl := time.Until(snap.ExpiresAt)
-	if ttl < 0 {
-		return &CheckResponse{Exists: false}, nil
-	}
 	return &CheckResponse{
 		Exists:           true,
 		InitiatorReady:   snap.InitiatorSubmitted,
 		AllowResubmit:    snap.AllowResubmit,
+		IgnoreWs:         snap.IgnoreWs,
 		ParticipantCount: len(snap.Participants),
-		TTLSeconds:       int64(ttl.Seconds()),
+		// -1 表示会话由发起方在线决定生命周期
+		TTLSeconds:       -1,
 	}, nil
 }
 
@@ -221,6 +322,80 @@ func (s *Service) SetResubmit(ctx context.Context, sessionID string, allow bool)
 	return s.GetSession(ctx, sessionID)
 }
 
+func (s *Service) SetIgnoreWs(ctx context.Context, sessionID string, ignore bool) (*SessionResponse, error) {
+	if err := s.store.SetIgnoreWs(ctx, sessionID, ignore); err != nil {
+		if errors.Is(err, store.ErrSessionNotFound) {
+			return nil, ErrSessionNotFound
+		}
+		s.logger.Error("set ignore_ws failed", zap.Error(err),
+			zap.String("session_id", truncateSessionID(sessionID)))
+		return nil, fmt.Errorf("set ignore_ws: %w", err)
+	}
+	// 切换后按新规则重新计算所有已提交的 match
+	if err := s.store.RecalcMatches(ctx, sessionID, ignore); err != nil {
+		s.logger.Warn("recalc matches failed (non-fatal)", zap.Error(err),
+			zap.String("session_id", truncateSessionID(sessionID)))
+	}
+	s.logger.Info("ignore_ws changed",
+		zap.String("session_id", truncateSessionID(sessionID)),
+		zap.Bool("ignore", ignore),
+	)
+	return s.GetSession(ctx, sessionID)
+}
+
+// ── UpdateParticipantNickname 参与者修改自己的昵称 ──
+
+func (s *Service) UpdateParticipantNickname(ctx context.Context, sessionID, oldNick, newNick string) error {
+	if oldNick == newNick {
+		return nil // 无变化
+	}
+	// 先查会话，拿到 oldNick 的 browserId（用于判断是否和冲突方是同一个浏览器）
+	snap, err := s.store.Get(ctx, sessionID)
+	if err != nil {
+		if errors.Is(err, store.ErrSessionNotFound) {
+			return ErrSessionNotFound
+		}
+		return err
+	}
+
+	// 找 oldNick 的 browserId
+	var oldBrowserID string
+	for _, p := range snap.Participants {
+		if p.Nickname == oldNick {
+			oldBrowserID = p.BrowserID
+			break
+		}
+	}
+
+	// 发起方昵称冲突检测（同浏览器跳过）
+	if snap.InitiatorNickname == newNick {
+		if snap.InitiatorBrowserID == "" || snap.InitiatorBrowserID != oldBrowserID {
+			return &BusinessError{Code: ErrCodeNicknameExists, Message: "该昵称已被发起方使用"}
+		}
+	}
+	err = s.store.UpdateParticipantNickname(ctx, sessionID, oldNick, newNick, oldBrowserID)
+	if err != nil {
+		switch {
+		case errors.Is(err, store.ErrSessionNotFound):
+			return ErrSessionNotFound
+		case errors.Is(err, store.ErrOldNotFound):
+			return &BusinessError{Code: ErrCodeNotInSession}
+		case errors.Is(err, store.ErrNicknameConflict):
+			return &BusinessError{Code: ErrCodeNicknameExists, Message: "该昵称已被其他参与者使用"}
+		default:
+			s.logger.Error("update participant nickname failed", zap.Error(err),
+				zap.String("session_id", truncateSessionID(sessionID)))
+			return fmt.Errorf("update nickname: %w", err)
+		}
+	}
+	s.logger.Info("participant renamed",
+		zap.String("session_id", truncateSessionID(sessionID)),
+		zap.String("old", oldNick),
+		zap.String("new", newNick),
+	)
+	return nil
+}
+
 // ── EndSession 发起方结束会话（删除 Redis key，WS 广播由 handler 完成） ──
 
 func (s *Service) EndSession(ctx context.Context, sessionID string) error {
@@ -235,6 +410,25 @@ func (s *Service) EndSession(ctx context.Context, sessionID string) error {
 	return nil
 }
 
+// ── RemoveParticipant 参与者主动离开（从 Redis 删除其字段） ──
+
+func (s *Service) RemoveParticipant(ctx context.Context, sessionID, nickname string) error {
+	err := s.store.RemoveParticipant(ctx, sessionID, nickname)
+	if err != nil {
+		if errors.Is(err, store.ErrSessionNotFound) {
+			return ErrSessionNotFound
+		}
+		s.logger.Warn("remove participant failed", zap.Error(err),
+			zap.String("session_id", truncateSessionID(sessionID)),
+			zap.String("nickname", nickname))
+		return err
+	}
+	s.logger.Info("participant removed",
+		zap.String("session_id", truncateSessionID(sessionID)),
+		zap.String("nickname", nickname))
+	return nil
+}
+
 func truncateSessionID(id string) string {
 	if len(id) > 8 {
 		return id[:8] + "..."
diff --git a/server/internal/tools/dual_check/ws_handler.go b/server/internal/tools/dual_check/ws_handler.go
index 2d14110..f05a040 100644
--- a/server/internal/tools/dual_check/ws_handler.go
+++ b/server/internal/tools/dual_check/ws_handler.go
@@ -3,8 +3,11 @@ package dual_check
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
+	"strings"
+	"unicode/utf8"
 
 	pkgws "cancerai.top/toolbox-server/internal/pkg/websocket"
 	"cancerai.top/toolbox-server/internal/response"
@@ -35,6 +38,7 @@ func (h *WSHandler) Handle(c *gin.Context) {
 	sessionID := c.Query("session_id")
 	role := c.Query("role")
 	nickname := c.Query("nickname")
+	browserID := c.Query("browser_id")
 
 	if sessionID == "" {
 		c.JSON(http.StatusBadRequest, gin.H{"code": 4000, "message": "session_id required"})
@@ -44,7 +48,7 @@ func (h *WSHandler) Handle(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"code": 1004, "message": "role must be initiator or participant"})
 		return
 	}
-	if nickname == "" || len(nickname) > 32 {
+	if nickname == "" || utf8.RuneCountInString(nickname) > 32 {
 		c.JSON(http.StatusBadRequest, gin.H{"code": 4000, "message": "nickname required (1-32)"})
 		return
 	}
@@ -71,11 +75,27 @@ func (h *WSHandler) Handle(c *gin.Context) {
 	}
 	h.hub.Register(wsConn)
 
-	// 参与者首次连接：自动登记昵称（幂等）
+	// 参与者首次连接：自动登记昵称（冲突时自动改名）
+	actualNick := nickname
 	if role == "participant" {
-		_, _ = h.service.JoinParticipant(c.Request.Context(), sessionID, nickname)
-		// 广播 participant_joined 给房间其他人
-		h.hub.Broadcast(sessionID, response.WSParticipantJoined(nickname))
+		_, actual, err := h.service.JoinParticipant(c.Request.Context(), sessionID, nickname, browserID)
+		if err == nil {
+			actualNick = actual
+			if actualNick != nickname {
+				// 自动改名：通知客户端 + 用 actualNick 广播
+				wsConn.Send <- marshalMsg(response.WSNicknameAutoChanged(actualNick))
+				h.logger.Info("ws participant auto-renamed",
+					zap.String("session_id", truncateSessionID(sessionID)),
+					zap.String("original", nickname),
+					zap.String("actual", actualNick))
+			}
+			h.hub.Broadcast(sessionID, response.WSParticipantJoined(actualNick))
+		} else {
+			h.logger.Warn("ws JoinParticipant failed",
+				zap.String("session_id", truncateSessionID(sessionID)),
+				zap.String("nickname", nickname),
+				zap.Error(err))
+		}
 	}
 
 	// 推一个 init 消息给新连接者，带上当前全量快照让它自己初始化 UI
@@ -91,10 +111,13 @@ func (h *WSHandler) Handle(c *gin.Context) {
 
 	go pkgws.WritePump(wsConn)
 	// ReadPump 里的 Unregister 会触发 participant_left 广播
-	go h.readLoop(wsConn, nickname)
+	go h.readLoop(wsConn, actualNick)
 }
 
-func (h *WSHandler) readLoop(c *pkgws.Conn, nickname string) {
+func (h *WSHandler) readLoop(c *pkgws.Conn, initialNickname string) {
+	// currentNick 是可变的，rename 成功后更新，保证 defer 中的 participant_left 广播用最新昵称
+	currentNick := initialNickname
+
 	defer func() {
 		c.WS.Close() // 先关，让 WritePump 也能退
 		if c.Role == "initiator" {
@@ -107,19 +130,87 @@ func (h *WSHandler) readLoop(c *pkgws.Conn, nickname string) {
 			} else {
 				h.logger.Info("initiator disconnected, session ended",
 					zap.String("session_id", truncateSessionID(c.SessionID)),
-					zap.String("nickname", nickname))
+					zap.String("nickname", currentNick))
 			}
 		} else {
-			// 参与者断开：广播 participant_left
-			h.hub.Broadcast(c.SessionID, response.WSParticipantLeft(nickname))
+			// 参与者断开：先从 Redis 删除字段，再广播 participant_left
+			if err := h.service.RemoveParticipant(context.Background(), c.SessionID, currentNick); err != nil {
+				h.logger.Warn("participant RemoveParticipant err",
+					zap.String("session_id", truncateSessionID(c.SessionID)),
+					zap.String("nickname", currentNick),
+					zap.Error(err))
+			}
+			h.logger.Info("participant disconnected",
+				zap.String("session_id", truncateSessionID(c.SessionID)),
+				zap.String("nickname", currentNick))
+			h.hub.Broadcast(c.SessionID, response.WSParticipantLeft(currentNick))
 		}
 		c.Hub.Unregister(c) // 最后从房间移除
 	}()
+
 	c.WS.SetPongHandler(func(string) error { return nil })
 	for {
-		if _, _, err := c.WS.ReadMessage(); err != nil {
+		_, raw, err := c.WS.ReadMessage()
+		if err != nil {
 			return
 		}
+
+		// 解析客户端发来的消息
+		var msg struct {
+			Type string          `json:"type"`
+			Data json.RawMessage `json:"data,omitempty"`
+		}
+		if err := json.Unmarshal(raw, &msg); err != nil {
+			continue // 不是合法 JSON，忽略
+		}
+
+		switch msg.Type {
+		case "rename":
+			// 只有参与者允许改昵称
+			if c.Role != "participant" {
+				h.sendError(c, "rename not allowed for role "+c.Role)
+				continue
+			}
+			var data struct {
+				NewNickname string `json:"new_nickname"`
+			}
+			if err := json.Unmarshal(msg.Data, &data); err != nil || strings.TrimSpace(data.NewNickname) == "" || utf8.RuneCountInString(data.NewNickname) > 32 {
+				h.sendError(c, "invalid new_nickname")
+				continue
+			}
+			newNick := strings.TrimSpace(data.NewNickname)
+			if newNick == currentNick {
+				continue // 无变化
+			}
+			err := h.service.UpdateParticipantNickname(context.Background(), c.SessionID, currentNick, newNick)
+			if err != nil {
+				var be *BusinessError
+				if errors.As(err, &be) {
+					h.sendError(c, be.Error()) // 优先用自定义 Message，否则回退到 ErrMessage(code)
+				} else {
+					h.sendError(c, "rename failed: "+err.Error())
+				}
+				continue
+			}
+			// 成功：更新本地昵称 + 广播给房间其他人
+			oldNick := currentNick
+			currentNick = newNick
+			h.hub.Broadcast(c.SessionID, response.WSParticipantRenamed(oldNick, newNick))
+			h.logger.Info("ws rename success",
+				zap.String("session_id", truncateSessionID(c.SessionID)),
+				zap.String("old", oldNick),
+				zap.String("new", newNick),
+			)
+		}
+	}
+}
+
+// sendError 通过 WS 给客户端发送一个 error 消息
+func (h *WSHandler) sendError(c *pkgws.Conn, errMsg string) {
+	msg := response.WebSocketMessage{Type: "error", Error: errMsg}
+	select {
+	case c.Send <- marshalMsg(msg):
+	default:
 	}
 }