fix: 修复批量更新凭证明细与缓存TTL抖动

- BatchUpdateCredentials 返回 success/failed/results 及 success_ids/failed_ids

- billing jitteredTTL 改为只减不增，确保TTL不超上界

- crypto/rand 失败时随机ID降级避免 panic

- OpenAI SelectAccount 失败日志去重并补充字段

- 修复两处类型断言以通过 errcheck

backend/internal/handler/admin/account_handler.go

@@ -810,20 +810,38 @@ func (h *AccountHandler) BatchUpdateCredentials(c *gin.Context) {
 		updates = append(updates, accountUpdate{ID: accountID, Credentials: account.Credentials})
 	}
 
-	// 阶段二：依次更新，任何失败立即返回（避免部分成功部分失败）
+	// 阶段二：依次更新，返回每个账号的成功/失败明细，便于调用方重试
+	success := 0
+	failed := 0
+	successIDs := make([]int64, 0, len(updates))
+	failedIDs := make([]int64, 0, len(updates))
+	results := make([]gin.H, 0, len(updates))
 	for _, u := range updates {
-		updateInput := &service.UpdateAccountInput{
-			Credentials: u.Credentials,
-		}
+		updateInput := &service.UpdateAccountInput{Credentials: u.Credentials}
 		if _, err := h.adminService.UpdateAccount(ctx, u.ID, updateInput); err != nil {
-			response.Error(c, 500, fmt.Sprintf("Failed to update account %d: %v", u.ID, err))
-			return
+			failed++
+			failedIDs = append(failedIDs, u.ID)
+			results = append(results, gin.H{
+				"account_id": u.ID,
+				"success":    false,
+				"error":      err.Error(),
+			})
+			continue
 		}
+		success++
+		successIDs = append(successIDs, u.ID)
+		results = append(results, gin.H{
+			"account_id": u.ID,
+			"success":    true,
+		})
 	}
 
 	response.Success(c, gin.H{
-		"success": len(updates),
-		"failed":  0,
+		"success":     success,
+		"failed":      failed,
+		"success_ids": successIDs,
+		"failed_ids":  failedIDs,
+		"results":     results,
 	})
 }
 

backend/internal/handler/openai_gateway_handler.go

@@ -219,9 +219,8 @@ func (h *OpenAIGatewayHandler) Responses(c *gin.Context) {
 		log.Printf("[OpenAI Handler] Selecting account: groupID=%v model=%s", apiKey.GroupID, reqModel)
 		selection, err := h.gatewayService.SelectAccountWithLoadAwareness(c.Request.Context(), apiKey.GroupID, sessionHash, reqModel, failedAccountIDs)
 		if err != nil {
-			log.Printf("[OpenAI Handler] SelectAccount failed: %v", err)
+			log.Printf("[OpenAI Handler] SelectAccount failed: groupID=%v model=%s tried=%d err=%v", apiKey.GroupID, reqModel, len(failedAccountIDs), err)
 			if len(failedAccountIDs) == 0 {
-				log.Printf("[OpenAI Gateway] SelectAccount failed: %v", err)
 				h.handleStreamingAwareError(c, http.StatusServiceUnavailable, "api_error", "Service temporarily unavailable", streamStarted)
 				return
 			}