fix(antigravity): 使用 Contains 匹配 missing_project_id 错误信息

backend/internal/service/token_refresh_service.go

@@ -176,7 +176,7 @@ func (s *TokenRefreshService) refreshWithRetry(ctx context.Context, account *Acc
 			// Antigravity 账户：如果之前是因为缺少 project_id 而标记为 error，现在成功获取到了，清除错误状态
 			if account.Platform == PlatformAntigravity &&
 				account.Status == StatusError &&
-				strings.HasPrefix(account.ErrorMessage, "missing_project_id:") {
+				strings.Contains(account.ErrorMessage, "missing_project_id:") {
 				if clearErr := s.accountRepo.ClearError(ctx, account.ID); clearErr != nil {
 					log.Printf("[TokenRefresh] Failed to clear error status for account %d: %v", account.ID, clearErr)
 				} else {