perf(lastleg): batch receiving candidates and trace slow work invalidation

lastleg-service/src/main/java/com/baiyue/lastleg/appointmentwork/AppointmentWorkChanges.java

@@ -4,13 +4,15 @@ import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
-/** Original business commands invalidate the manifest atomically with their business write. */
+/** 原业务写入与工作清单失效保持在同一事务，不延后或绕过版本门禁。 */
 @Component
 public class AppointmentWorkChanges {
-    private final AppointmentWorkMapper mapper;
-    public AppointmentWorkChanges(AppointmentWorkMapper mapper) { this.mapper=mapper; }
+    private final AppointmentWorkStore store;
+    /** 复用工作事项持久层，统一记录守卫更新耗时。 */
+    public AppointmentWorkChanges(AppointmentWorkStore store) { this.store=store; }
+    /** 只标记需求变化，保留调用方原事务和异常语义。 */
     @Transactional(propagation=Propagation.MANDATORY)
     public void requirementsChanged() {
-        if(mapper.invalidateRequirements()!=1) throw AppointmentWorkPolicy.unavailable("工作事项同步守卫未初始化");
+        store.invalidateRequirements();
     }
 }

lastleg-service/src/main/java/com/baiyue/lastleg/appointmentwork/AppointmentWorkStore.java

@@ -1,6 +1,9 @@
 package com.baiyue.lastleg.appointmentwork;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 import org.springframework.stereotype.Component;
 import java.time.*;
 import java.util.*;
@@ -9,10 +12,25 @@ import static com.baiyue.lastleg.appointmentwork.AppointmentWorkPolicy.*;
 
 @Component
 public class AppointmentWorkStore {
+    private static final Logger LOG = LoggerFactory.getLogger(AppointmentWorkStore.class);
     public static final int MAX_ITEMS=10000;
     private final AppointmentWorkMapper mapper;
     private final ObjectMapper json;
     public AppointmentWorkStore(AppointmentWorkMapper mapper,ObjectMapper json) { this.mapper=mapper; this.json=json; }
+    /** 只测量守卫更新语句，不改变锁、事务或版本，用于区分慢写是否卡在该语句。 */
+    public void invalidateRequirements() {
+        long started = System.nanoTime();
+        try {
+            if (mapper.invalidateRequirements() != 1) throw unavailable("工作事项同步守卫未初始化");
+        } finally {
+            long elapsedMs = java.util.concurrent.TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - started);
+            if (elapsedMs >= 250) {
+                // 语句耗时可能包含等锁或连接等待，不能仅凭日志认定具体锁根因；不记录请求业务载荷。
+                LOG.warn("Appointment work guard update slow: elapsedMs={}, requestId={}, traceId={}",
+                    elapsedMs, MDC.get("requestId"), MDC.get("traceId"));
+            }
+        }
+    }
     public AppointmentWorkMapper.Guard lock() {
         var guard=mapper.lockGuard(); if(guard==null) throw unavailable("工作事项DDL尚未集成"); return guard;
     }