fix(p16/p13a): Task 3.3 三项清偿 —— 互选超时接线、随访审计、随访风险检测（负向验证已证守卫有牙）

P16-T13 互选超时接线：
- 缺陷本体：expires_at 全仓无人写入（配置 48h 在、confirm 的过期过滤在，唯独创建不赋值）
  → (expires_at IS NULL OR expires_at > NOW()) 恒真，「截止后48小时」窗口形同虚设
- 修复：createMutualConsent 新建时写 expires_at = 活动结束时间 + ActivityConfig.mutualDeadlineHours
  （已确认口径「截止后48小时」），活动缺失/无结束时间回退创建时刻
- 守卫：ActivityMutualConsentServiceTest 新增 2 用例；负向验证（摘掉写入）恰 2 红、其余 7 绿
- 原测试 expiredConsentRejectsConfirm 手动补 expires_at 恰好掩盖了创建侧缺陷，如实记录

P13A-T31 随访审计：
- assigned Counselor 读他人咨询正文/随访此前零审计 → getDetailForCounselor 接线
  recordSensitiveAccess(counseling_followup)；本人读自己与 manager 摘要视图不审计

P13A-T33 随访风险检测：
- detectCounselingRisk 此前只扫申请摘要 → addFollowup 正文接入同一检测（source=counseling），
  INV-013 加固：不记录正文只记级别（同 apply 模式）
- 守卫：CounselingFollowupAuditAndRiskGuardTest 4 用例（审计落库回查 ×2 + 风险事件落库回查 ×2），全绿

backend/src/main/java/com/danyang/match/platform/activity_mutual/service/ActivityMutualConsentService.java

@@ -1,15 +1,19 @@
 package com.danyang.match.platform.activity_mutual.service;
 
+import com.danyang.match.platform.activity.entity.Activity;
+import com.danyang.match.platform.activity.mapper.ActivityMapper;
 import com.danyang.match.platform.activity_mutual.dto.MutualInterestResultDTO;
 import com.danyang.match.platform.activity_mutual.entity.ActivityMutualConsent;
 import com.danyang.match.platform.activity_mutual.mapper.ActivityMutualConsentMapper;
 import com.danyang.match.platform.relationship.service.RelationshipService;
+import com.danyang.match.platform.shared.config.ActivityConfig;
 import com.danyang.match.platform.shared.constant.Constants;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.time.Duration;
 import java.time.Instant;
 import java.util.*;
 
@@ -20,6 +24,8 @@ public class ActivityMutualConsentService {
 
     private final ActivityMutualConsentMapper consentMapper;
     private final RelationshipService relationshipService;
+    private final ActivityMapper activityMapper;
+    private final ActivityConfig activityConfig;
 
     public List<MutualInterestResultDTO> detectMutualResults(String activityId) {
         List<ActivityMutualConsent> bothConfirmed = consentMapper.findBothConfirmedByActivity(activityId);
@@ -44,6 +50,15 @@ public class ActivityMutualConsentService {
             }
             consent.setUserAStatus(Constants.MUTUAL_CONSENT_STATUS_PENDING);
             consent.setUserBStatus(Constants.MUTUAL_CONSENT_STATUS_PENDING);
+            // P16-T13 接线：写入 expires_at，否则 confirmSideIfPending 的
+            // `(expires_at IS NULL OR expires_at > NOW())` 过滤因恒 NULL 而永不生效，
+            // 「截止后 48 小时」窗口（PENDING_DECISIONS 已确认口径）形同虚设。
+            // 基准点 = 活动结束时间（ActivityConfig.mutualDeadlineHours 注释的既定语义），
+            // 活动不存在或无结束时间时回退为创建时刻。
+            Instant deadlineBase = Optional.ofNullable(activityMapper.selectById(activityId))
+                    .map(Activity::getEndAt)
+                    .orElseGet(Instant::now);
+            consent.setExpiresAt(deadlineBase.plus(Duration.ofHours(activityConfig.getMutualDeadlineHours())));
             consentMapper.insert(consent);
         }
         return consent;

backend/src/main/java/com/danyang/match/platform/counseling/service/CounselingService.java

@@ -1,5 +1,6 @@
 package com.danyang.match.platform.counseling.service;
 
+import com.danyang.match.platform.audit.service.AuditLogService;
 import com.danyang.match.platform.counseling.entity.CounselingFollowup;
 import com.danyang.match.platform.counseling.entity.CounselingServiceRecord;
 import com.danyang.match.platform.counseling.mapper.CounselingFollowupMapper;
@@ -78,6 +79,7 @@ public class CounselingService {
     private final NotificationService notificationService;
     private final RiskReferralService riskReferralService;
     private final DataScopeGuard dataScopeGuard;
+    private final AuditLogService auditLogService;
 
     // ==================== 用户端：申请 ====================
 
@@ -264,6 +266,23 @@ public class CounselingService {
         fu.setResultCode(resultCode);
         fu.setNextFollowupAt(nextFollowupAt);
         followupMapper.insert(fu);
+
+        // P13A-T33: 随访正文与申请摘要共用同一风险检测（来源同为 source=counseling）。
+        // 随访由 counselor 撰写、更贴近用户近况，是风险关键词的另一个真实入口；
+        // 此前只有申请摘要（apply:133）被扫描，随访正文完全绕过风控。
+        // INV-013 加固同 apply：绝不记录正文，只记级别与记录 ID。
+        CounselingServiceRecord owner = mapper.findFull(serviceId);
+        if (owner != null) {
+            try {
+                String riskLevel = riskReferralService.detectCounselingRisk(owner.getUserId(), content);
+                if (riskLevel != null) {
+                    log.info("随访内容触发风险检测: serviceId={}, followupId={}, riskLevel={}",
+                            serviceId, fu.getId(), riskLevel);
+                }
+            } catch (Exception e) {
+                log.warn("随访风险检测异常: serviceId={}, err={}", serviceId, e.getMessage());
+            }
+        }
         return fu;
     }
 
@@ -333,6 +352,12 @@ public class CounselingService {
                     "INV-012: 只能查看分配给自己的咨询服务");
             return null;
         }
+        // P13A-T31: assigned Counselor 读取的是**他人**的咨询正文与随访记录 ——
+        // 敏感访问必须留痕（同 Phase 17 report/risk_profile 的 recordSensitiveAccess 模式）。
+        // 本人读自己的不算敏感访问；manager/matchmaker 走脱敏摘要视图，不触正文，无需审计。
+        if (isAssignedCounselor) {
+            auditLogService.recordSensitiveAccess(requesterId, "counseling_followup", serviceId);
+        }
         return svc;
     }