fix(agent): handle mid-stream quota_limit and upstream_waf_challenge with auto account rotation in runOpenAIAgentTurn

[Yash12212]

Problem Description:
When running multi-turn OpenAI Agent requests with tool-calling enabled via handleOpenAIAgentStream(), sendChatRequest() handles account failover only during connection establishment / preflight chunk 1.

However, if an upstream account hits its hourly quota limit mid-stream (code: 'quota_limit') or triggers WAF validation (code: 'upstream_waf_challenge'), assertNoUpstreamFailure() in openai-agent-runtime.js throws an UpstreamResponseError. Because collectOpenAIAgentAttempt() inside runOpenAIAgentTurn() is not caught for account-level rotation, the error bubbles directly to chat.js, returning 502 Qwen 上游返回业务错误 to the client instead of auto-rotating to another healthy account in the pool.

Stack Trace:

[ERROR] [AGENT] ❌ OpenAI Agent 回合处理失败
UpstreamResponseError: Qwen 上游返回业务错误
    at assertNoUpstreamFailure (src/utils/upstream-error.js:41:11)
    at src/utils/openai-agent-runtime.js:138:5
    at consumeFrames (src/utils/sse.js:153:19)
    at async collectOpenAIAgentAttempt (src/utils/openai-agent-runtime.js:134:24)
    at async runOpenAIAgentTurn (src/utils/openai-agent-runtime.js:423:21)
    ...
  code: 'quota_limit',
  publicMessage: 'Qwen 上游返回业务错误'

Proposed Solution / Diff:
In src/utils/openai-agent-runtime.js, catch UpstreamResponseError for quota_limit / upstream_waf_challenge, record the cooldown against the exhausted account, and invoke requestSender without account binding to rotate to the next available account in the pool:

--- a/src/utils/openai-agent-runtime.js
+++ b/src/utils/openai-agent-runtime.js
@@ -7,7 +7,8 @@ const {
 } = require('./tool-prompt.js')
 const { consumeSSEStream, createUpstreamResponseFilter } = require('./sse.js')
 const { createUpstreamDeltaNormalizer } = require('./chat-helpers.js')
-const { assertNoUpstreamFailure } = require('./upstream-error.js')
+const { assertNoUpstreamFailure, UpstreamResponseError } = require('./upstream-error.js')
+const accountManager = require('./account.js')
 const {
   parseAgentControlText,
   createAgentControlStreamParser,
@@ -420,10 +421,43 @@ const runOpenAIAgentTurn = async (initialResponse, options = {}) => {
 
   for (let attemptNumber = 1; attemptNumber <= maxAttempts; attemptNumber++) {
     attemptsMade = attemptNumber
-    const attempt = await collectOpenAIAgentAttempt(currentResponse, {
-      ...options,
-      attempt_number: attemptNumber
-    })
+    let attempt
+    try {
+      attempt = await collectOpenAIAgentAttempt(currentResponse, {
+        ...options,
+        attempt_number: attemptNumber
+      })
+    } catch (streamErr) {
+      if (streamErr instanceof UpstreamResponseError && (streamErr.code === 'quota_limit' || streamErr.code === 'upstream_waf_challenge')) {
+        const activeAccount = options.currentAccount?.email || upstreamContext.currentAccount?.email
+        if (activeAccount) {
+          if (streamErr.code === 'quota_limit') {
+            logger.warn(`Agent attempt ${attemptNumber} 遭遇配额耗尽 (${activeAccount})，已置入冷却并自动轮换账户重试`, 'AGENT')
+            accountManager.recordAccountQuotaLimit(activeAccount)
+          } else {
+            logger.warn(`Agent attempt ${attemptNumber} 遭遇 WAF 验证 (${activeAccount})，已置入冷却并自动轮换账户重试`, 'AGENT')
+            accountManager.recordAccountFailure(activeAccount, 'WAF_CHALLENGE')
+          }
+        }
+        if (typeof requestSender === 'function' && attemptNumber < maxAttempts) {
+          const rotateResponse = await requestSender(retryBaseBody, {
+            chatId: null,
+            parentId: null,
+            currentAccount: null,
+            agentRetry: true
+          })
+          if (rotateResponse?.status && rotateResponse.response) {
+            currentResponse = rotateResponse.response
+            upstreamContext = mergePresent(upstreamContext, {
+              chatId: rotateResponse.chatId,
+              currentAccount: rotateResponse.currentAccount
+            })
+            continue
+          }
+        }
+      }
+      throw streamErr
+    }