fix(matchmaker): 受控联系审计 afterData 改 JSON 序列化（运行时实测抓到 PG jsonb 500）

- 根因：ContactAuthorizationService 7 处 saveAudit afterData 传 key=value 裸串，PG audit_logs.after_data 为 jsonb 严格解析 → request/disclose 全链路 500；H2 测试库该列 CLOB 不校验 → 集成测试假绿
- 修复：新增 jsonOf 辅助（Jackson writeValueAsString，成对 kv），7 调用点全部改写；purpose/reason 用户输入由 Jackson 转义防 JSON 注入
- 守卫加固：MatchmakerContactAuthorizationTest 审计断言补「afterData 必须可 JSON 解析且为对象」（readTree 真解析）——运行时事故进入自动化基线
- 同型排查：全仓 recordSensitiveAccess/saveAuditLog 其他调用点 afterData 干净，污染面仅本文件
- 验证：定向 20/20（授权 13+disabled 2+守卫 5）；负向注入还原裸串 → 恰好 JSON 解析守卫判红（错误信息与生产一致 Unrecognized token 'channel'）→ 还原复绿
- 发现渠道：本地栈运行时实测（V056 上线后首次真 PG 验证），非测试环境

backend/src/main/java/com/danyang/match/platform/matchmaker/service/ContactAuthorizationService.java

@@ -1,5 +1,7 @@
 package com.danyang.match.platform.matchmaker.service;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.danyang.match.platform.audit.entity.AuditLog;
 import com.danyang.match.platform.audit.entity.SensitiveAccessLog;
 import com.danyang.match.platform.audit.mapper.AuditLogMapper;
@@ -23,6 +25,7 @@ import org.springframework.transaction.annotation.Transactional;
 import java.time.Instant;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -76,6 +79,9 @@ public class ContactAuthorizationService {
     private final SensitiveAccessLogMapper sensitiveAccessLogMapper;
     private final UserMapper userMapper;
 
+    /** afterData JSON 序列化（静态初始化，不参与构造注入，避免测试桩连带改动）。 */
+    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+
     // ==================== ① request：红娘发起申请 ====================
 
     @Transactional
@@ -122,7 +128,7 @@ public class ContactAuthorizationService {
                 auth.getId(), operatorId, userId, channel);
         saveAudit(operatorId, Constants.CONTACT_AUDIT_ACTION_REQUEST, auth.getId(),
                 assignment != null ? assignment.getId() : null,
-                "matchmaker.contact.request", "channel=" + channel + ";purpose=" + auth.getPurpose());
+                "matchmaker.contact.request", jsonOf("channel", channel, "purpose", auth.getPurpose()));
         return auth;
     }
 
@@ -207,7 +213,7 @@ public class ContactAuthorizationService {
         log.info("受控联系授权审批通过: authId={}, approver={}", authId, approverOperatorId);
         saveAudit(approverOperatorId, Constants.CONTACT_AUDIT_ACTION_APPROVE, authId,
                 activeAssignmentIdOf(auth), "matchmaker.contact.approve",
-                "result=approved;channel=" + auth.getChannel());
+                jsonOf("result", "approved", "channel", auth.getChannel()));
         return auth;
     }
 
@@ -230,7 +236,7 @@ public class ContactAuthorizationService {
         log.info("受控联系授权审批拒绝: authId={}, approver={}", authId, approverOperatorId);
         saveAudit(approverOperatorId, Constants.CONTACT_AUDIT_ACTION_APPROVE, authId,
                 activeAssignmentIdOf(auth), "matchmaker.contact.approve",
-                "result=rejected;channel=" + auth.getChannel());
+                jsonOf("result", "rejected", "channel", auth.getChannel()));
         return auth;
     }
 
@@ -251,7 +257,7 @@ public class ContactAuthorizationService {
         log.info("受控联系授权用户同意: authId={}, userId={}", authId, userId);
         saveAudit(userId, Constants.CONTACT_AUDIT_ACTION_CONSENT, authId,
                 activeAssignmentIdOf(auth), "matchmaker.contact.consent",
-                "channel=" + auth.getChannel());
+                jsonOf("channel", auth.getChannel()));
         return auth;
     }
 
@@ -268,7 +274,7 @@ public class ContactAuthorizationService {
         log.info("受控联系授权用户拒绝: authId={}, userId={}", authId, userId);
         saveAudit(userId, Constants.CONTACT_AUDIT_ACTION_DECLINE, authId,
                 activeAssignmentIdOf(auth), "matchmaker.contact.decline",
-                "channel=" + auth.getChannel());
+                jsonOf("channel", auth.getChannel()));
         return auth;
     }
 
@@ -301,7 +307,7 @@ public class ContactAuthorizationService {
         log.info("受控联系授权撤销: authId={}, by={}", authId, operatorId);
         saveAudit(operatorId, Constants.CONTACT_AUDIT_ACTION_REVOKE, authId,
                 activeAssignmentIdOf(auth), "matchmaker.contact.revoke",
-                "reason=" + auth.getRevokeReason());
+                jsonOf("reason", auth.getRevokeReason()));
         return auth;
     }
 
@@ -347,7 +353,7 @@ public class ContactAuthorizationService {
                 auth.getId(), operatorId, userId, auth.getChannel());
         saveAudit(operatorId, Constants.CONTACT_AUDIT_ACTION_DISCLOSE, auth.getId(),
                 assignment != null ? assignment.getId() : null,
-                "matchmaker.contact.disclose", "channel=" + auth.getChannel());
+                "matchmaker.contact.disclose", jsonOf("channel", auth.getChannel()));
 
         Map<String, Object> result = new HashMap<>();
         result.put("phone", phone);
@@ -447,4 +453,24 @@ public class ContactAuthorizationService {
         auditLog.setRequestTraceId(MDC.get("requestId"));
         auditLogMapper.insert(auditLog);
     }
+
+    /**
+     * afterData 必须是合法 JSON（PG audit_logs.after_data 为 jsonb 严格解析；
+     * H2 测试库 CLOB 不校验——裸 key=value 拼接在测试侧假绿、生产侧 500）。
+     * kv 成对传入，Jackson 负责用户输入（purpose/reason）的 JSON 转义，防 JSON 注入。
+     */
+    private String jsonOf(Object... kvPairs) {
+        if (kvPairs.length % 2 != 0) {
+            throw new IllegalStateException("jsonOf requires key-value pairs");
+        }
+        Map<String, Object> data = new LinkedHashMap<>();
+        for (int i = 0; i < kvPairs.length; i += 2) {
+            data.put(String.valueOf(kvPairs[i]), kvPairs[i + 1]);
+        }
+        try {
+            return OBJECT_MAPPER.writeValueAsString(data);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException("audit afterData JSON serialization failed", e);
+        }
+    }
 }

backend/src/test/java/com/danyang/match/platform/matchmaker/MatchmakerContactAuthorizationTest.java

@@ -238,6 +238,13 @@ class MatchmakerContactAuthorizationTest {
                     pair[0] + " 必须携带请求追踪 ID");
             assertFalse(String.valueOf(audit.getAfterData()).contains(userPhone),
                     pair[0] + " 审计内容不得含 phone");
+            // afterData 必须是合法 JSON（PG audit_logs.after_data 为 jsonb 严格解析；
+            // H2 CLOB 不校验——裸 key=value 拼接在测试侧假绿、生产侧 500，此断言为运行时事故回归守卫）
+            com.fasterxml.jackson.databind.JsonNode afterJson =
+                    assertDoesNotThrow(() -> new com.fasterxml.jackson.databind.ObjectMapper()
+                            .readTree(String.valueOf(audit.getAfterData())),
+                            pair[0] + " afterData 必须可 JSON 解析（PG jsonb 严格校验口径）");
+            assertTrue(afterJson.isObject(), pair[0] + " afterData 必须是 JSON 对象");
         }
     }