feat(queue): 优化用户消息队列锁释放时机

将队列锁释放时机从"请求完成后"提前到"请求发送后"，因为 Claude API
限流（RPM）基于请求发送时刻计算，无需等待响应完成。

主要变更：
- 移除锁续租机制（startLockRenewal、refreshUserMessageLock）
- 所有 relay 服务在请求发送成功后立即释放锁
- 流式请求通过 onResponseStart 回调在收到响应头时释放
- 调整默认配置：timeoutMs 60s→5s，lockTtlMs 120s→5s
- 新增 USER_MESSAGE_QUEUE_LOCK_TTL_MS 环境变量支持

src/services/claudeRelayService.js

@@ -151,7 +151,6 @@ class ClaudeRelayService {
     let upstreamRequest = null
     let queueLockAcquired = false
     let queueRequestId = null
-    let queueLockRenewalStopper = null
     let selectedAccountId = null
 
     try {
@@ -255,10 +254,6 @@ class ClaudeRelayService {
         if (queueResult.acquired && !queueResult.skipped) {
           queueLockAcquired = true
           queueRequestId = queueResult.requestId
-          queueLockRenewalStopper = await userMessageQueueService.startLockRenewal(
-            accountId,
-            queueRequestId
-          )
           logger.debug(
             `📬 User message queue lock acquired for account ${accountId}, requestId: ${queueRequestId}`
           )
@@ -339,6 +334,23 @@ class ClaudeRelayService {
         options
       )
 
+      // 📬 请求已发送成功，立即释放队列锁（无需等待响应处理完成）
+      // 因为 Claude API 限流基于请求发送时刻计算（RPM），不是请求完成时刻
+      if (queueLockAcquired && queueRequestId && selectedAccountId) {
+        try {
+          await userMessageQueueService.releaseQueueLock(selectedAccountId, queueRequestId)
+          queueLockAcquired = false // 标记已释放，防止 finally 重复释放
+          logger.debug(
+            `📬 User message queue lock released early for account ${selectedAccountId}, requestId: ${queueRequestId}`
+          )
+        } catch (releaseError) {
+          logger.error(
+            `❌ Failed to release user message queue lock early for account ${selectedAccountId}:`,
+            releaseError.message
+          )
+        }
+      }
+
       response.accountId = accountId
       response.accountType = accountType
 
@@ -608,13 +620,13 @@ class ClaudeRelayService {
       )
       throw error
     } finally {
-      // 📬 释放用户消息队列锁
+      // 📬 释放用户消息队列锁（兜底，正常情况下已在请求发送后提前释放）
       if (queueLockAcquired && queueRequestId && selectedAccountId) {
         try {
-          if (queueLockRenewalStopper) {
-            queueLockRenewalStopper()
-          }
           await userMessageQueueService.releaseQueueLock(selectedAccountId, queueRequestId)
+          logger.debug(
+            `📬 User message queue lock released in finally for account ${selectedAccountId}, requestId: ${queueRequestId}`
+          )
         } catch (releaseError) {
           logger.error(
             `❌ Failed to release user message queue lock for account ${selectedAccountId}:`,
@@ -1245,7 +1257,6 @@ class ClaudeRelayService {
   ) {
     let queueLockAcquired = false
     let queueRequestId = null
-    let queueLockRenewalStopper = null
     let selectedAccountId = null
 
     try {
@@ -1350,10 +1361,6 @@ class ClaudeRelayService {
         if (queueResult.acquired && !queueResult.skipped) {
           queueLockAcquired = true
           queueRequestId = queueResult.requestId
-          queueLockRenewalStopper = await userMessageQueueService.startLockRenewal(
-            accountId,
-            queueRequestId
-          )
           logger.debug(
             `📬 User message queue lock acquired for account ${accountId} (stream), requestId: ${queueRequestId}`
           )
@@ -1425,19 +1432,36 @@ class ClaudeRelayService {
         sessionHash,
         streamTransformer,
         options,
-        isDedicatedOfficialAccount
+        isDedicatedOfficialAccount,
+        // 📬 新增回调：在收到响应头时释放队列锁
+        async () => {
+          if (queueLockAcquired && queueRequestId && selectedAccountId) {
+            try {
+              await userMessageQueueService.releaseQueueLock(selectedAccountId, queueRequestId)
+              queueLockAcquired = false // 标记已释放，防止 finally 重复释放
+              logger.debug(
+                `📬 User message queue lock released early for stream account ${selectedAccountId}, requestId: ${queueRequestId}`
+              )
+            } catch (releaseError) {
+              logger.error(
+                `❌ Failed to release user message queue lock early for stream account ${selectedAccountId}:`,
+                releaseError.message
+              )
+            }
+          }
+        }
       )
     } catch (error) {
       logger.error(`❌ Claude stream relay with usage capture failed:`, error)
       throw error
     } finally {
-      // 📬 释放用户消息队列锁
+      // 📬 释放用户消息队列锁（兜底，正常情况下已在收到响应头后提前释放）
       if (queueLockAcquired && queueRequestId && selectedAccountId) {
         try {
-          if (queueLockRenewalStopper) {
-            queueLockRenewalStopper()
-          }
           await userMessageQueueService.releaseQueueLock(selectedAccountId, queueRequestId)
+          logger.debug(
+            `📬 User message queue lock released in finally for stream account ${selectedAccountId}, requestId: ${queueRequestId}`
+          )
         } catch (releaseError) {
           logger.error(
             `❌ Failed to release user message queue lock for stream account ${selectedAccountId}:`,
@@ -1461,7 +1485,8 @@ class ClaudeRelayService {
     sessionHash,
     streamTransformer = null,
     requestOptions = {},
-    isDedicatedOfficialAccount = false
+    isDedicatedOfficialAccount = false,
+    onResponseStart = null // 📬 新增：收到响应头时的回调，用于提前释放队列锁
   ) {
     // 获取账户信息用于统一 User-Agent
     const account = await claudeAccountService.getAccount(accountId)
@@ -1707,6 +1732,16 @@ class ClaudeRelayService {
           return
         }
 
+        // 📬 收到成功响应头（HTTP 200），立即调用回调释放队列锁
+        // 此时请求已被 Claude API 接受并计入 RPM 配额，无需等待响应完成
+        if (onResponseStart && typeof onResponseStart === 'function') {
+          try {
+            await onResponseStart()
+          } catch (callbackError) {
+            logger.error('❌ Error in onResponseStart callback:', callbackError.message)
+          }
+        }
+
         let buffer = ''
         const allUsageData = [] // 收集所有的usage事件
         let currentUsageData = {} // 当前正在收集的usage数据