fix(delay): write pending state once per node in batch checks

checkListDelay pre-marked every node as checking, help() re-marked it
when picked up and measureDelay marked it a third time on entry, so
each batch run queued three identical pending updates per node. Keep
the pre-mark (immediate feedback for queued nodes) and drop the
redundant marks along the chain.

src/services/delay.ts

@@ -277,6 +277,8 @@ class DelayManager {
     group: string,
     timeout: number,
   ): Promise<DelayUpdate> {
+    // Entry points own the pending mark; measureDelay only writes results.
+    this.setDelay(member.ref.name, group, -2)
     const update = await this.measureDelay(member, group, timeout)
     this.queueGroupNotification(group)
     return update
@@ -298,8 +300,6 @@ class DelayManager {
       `[DelayManager] 开始测试延迟，代理: ${name}, 组: ${group}, 超时: ${timeout}ms`,
     )
 
-    this.setDelay(name, group, -2)
-
     const startTime = Date.now()
 
     try {
@@ -359,8 +359,6 @@ class DelayManager {
       const currName = currMember.ref.name
 
       try {
-        this.setDelay(currName, group, -2)
-
         // Stagger requests so a batch does not hit the core at once.
         if (index > 1) {
           await new Promise((resolve) =>