[Bug] Sandbox fails to start for hours - "The sandbox failed to start. Please try again later." #1266

提交前确认 · Pre-submission checklist

• 我已搜索过现有 issue，确认这不是重复 / I searched existing issues and confirmed this isn't a duplicate.
• 我已阅读 CONTRIBUTING.md / I've read CONTRIBUTING.md.

问题类别 · Category

其他 / 不确定 · Other / Not sure

涉及的 Agent 框架 · Agent framework

ZCode Agent（自研）

严重程度 · Severity

阻塞使用 · Blocking (无法使用核心功能 / core function unusable)

复现频率 · Reproducibility

必现 · Always

问题描述 · Description

The sandbox in Z.AI Chat (web) has been failing to start for several hours.
Every tool call (Bash, Read, Write, LS) returns:
"The sandbox failed to start. Please try again later. Do not call sandbox tools again in this message."

• Session ID: web-2e5101de-58ba-466f-b083-7a54f0295f0e
• Chat ID: 6740e571-5ca6-4c90-a28b-1b86dfb686c4
• Trace IDs: 1a17da5fec2f6a7d, 1a17db64968bde49, 1a17db40968c1d91
• Time observed: from ~2026-10-27 evening (UTC+8), still failing now
• Impact: I cannot access project files (including finished deliverables in
  /home/z/my-project/download/) or run any code. The project is fully blocked.
• Request: please check the sandbox backend for this session/workspace and
  restore it. Files must be preserved.

复现步骤 · Steps to reproduce

1

期望表现 · Expected behavior

1

实际表现 · Actual behavior

1

ZCode 版本 · ZCode version

1

设备 / 系统 / 浏览器 · Device / OS / Browser

1

截图 / 录屏 / 日志 · Screenshots / Recordings / Logs

No response