feat(auth): Add retry logic with exponential backoff for S2A and Codex API

- Add exponential backoff with jitter to S2A OAuth submission (3 attempts)
- Implement 5xx error retry mechanism in Codex API workspace selection (5 attempts)
- Add 429 rate limit handling with retry support in Codex API
- Improve team member processing with staggered delays to avoid concurrent conflicts
- Add per-attempt proxy rotation to avoid reusing failed proxies
- Enhance retry delay calculation with random jitter to prevent thundering herd
- Update logging to display retry attempts and delay durations
- Improve error messages with HTTP status codes and response body snippets
- Refactor retry loops to use consistent exponential backoff pattern across modules

backend/internal/api/team_process.go

@@ -3,6 +3,7 @@ package api
 import (
 	"encoding/json"
 	"fmt"
+	"math/rand"
 	"net/http"
 	"strings"
 	"sync"
@@ -775,24 +776,31 @@ func processSingleTeam(idx int, req TeamProcessRequest) (result TeamProcessResul
 		}
 		defer func() { <-s2aSem }()
 
-		// 从代理池获取随机代理（默认轮询使用代理池，无代理则直连）
-		proxyToUse, _ := database.Instance.GetRandomCodexProxy()
-		proxyDisplay := "直连"
-		if proxyToUse != "" {
-			proxyDisplay = getProxyDisplay(proxyToUse)
-		}
-		logger.Status(fmt.Sprintf("%s 入库中... | 邮箱: %s | 代理: %s", memberLogPrefix, memberEmail, proxyDisplay), memberEmail, "team")
-
 		var s2aSuccess bool
 		var lastError string
 
-		for attempt := 0; attempt < 2; attempt++ { // 最多重试1次
+		for attempt := 0; attempt < 3; attempt++ { // 最多重试2次
 			// 检查停止信号
 			if isStopped() {
 				return false
 			}
 			if attempt > 0 {
-				logger.Warning(fmt.Sprintf("%s 入库重试 (第%d次)", memberLogPrefix, attempt+1), memberEmail, "team")
+				// 重试前等待一段时间，避免密集请求
+				retryDelay := time.Duration(3+attempt*2) * time.Second
+				logger.Warning(fmt.Sprintf("%s 入库重试 (第%d次, 等待 %ds)", memberLogPrefix, attempt+1, int(retryDelay.Seconds())), memberEmail, "team")
+				time.Sleep(retryDelay)
+			}
+
+			// 每次尝试都从代理池获取新代理（避免复用失败代理）
+			proxyToUse, _ := database.Instance.GetRandomCodexProxy()
+			proxyDisplay := "直连"
+			if proxyToUse != "" {
+				proxyDisplay = getProxyDisplay(proxyToUse)
+			}
+			if attempt == 0 {
+				logger.Status(fmt.Sprintf("%s 入库中... | 邮箱: %s | 代理: %s", memberLogPrefix, memberEmail, proxyDisplay), memberEmail, "team")
+			} else {
+				logger.Status(fmt.Sprintf("%s 入库重试中... | 代理: %s", memberLogPrefix, proxyDisplay), memberEmail, "team")
 			}
 
 			// 创建日志回调 - 只显示关键步骤
@@ -948,13 +956,14 @@ func processSingleTeam(idx int, req TeamProcessRequest) (result TeamProcessResul
 			memberMu.Unlock()
 			logger.Success(fmt.Sprintf("%s ✓ 注册成功 (耗时: %.1fs)", memberLogPrefix, regDuration.Seconds()), currentEmail, "team")
 
-			// 流水线：注册成功后等待 3 秒再开始入库（避免触发邮箱验证）
+			// 流水线：注册成功后等待再开始入库（避免触发邮箱验证 + 成员间错开避免并发冲突）
 			s2aWg.Add(1)
 			go func(idx int, e, p string) {
 				defer s2aWg.Done()
-				// 等待 3 秒，让账号状态稳定（可被停止信号中断）
+				// 基础 3 秒 + 成员索引 * 2 秒错开 + 0~2 秒随机抖动，避免同 Team 多成员同时选工作区
+				stagger := 3*time.Second + time.Duration(idx*2)*time.Second + time.Duration(rand.Intn(2000))*time.Millisecond
 				select {
-				case <-time.After(3 * time.Second):
+				case <-time.After(stagger):
 				case <-teamProcessState.stopCh:
 					return
 				}