[BUG] MCP stdio servers torn down during plugin autoupdate, do not auto-respawn

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

MCP stdio servers (Telegram MCP, custom bigin-mcp, etc.) get torn down when Claude Code performs a plugin autoupdate mid-session. The child processes terminate and are never re-spawned. Tools become unavailable for the rest of the session. Manually killing any stray child processes (python.exe / node.exe) does not trigger respawn either. Only a full Claude Code restart recovers.

Environment: Claude Code CLI on Windows 11 Pro, plugins with stdio MCP servers, auto-update enabled.

Repro:

1. Configure an MCP stdio server in .mcp.json (or via plugin).
2. Confirm tools are available via /mcp (server shows connected).
3. Let CC perform a plugin autoupdate mid-session.
4. Server shows disconnected; tools become unavailable.
5. No auto-respawn — survives until full CC relaunch.

What Should Happen?

Plugin autoupdate should either:
(a) not tear down active MCP stdio child processes during the update, OR
(b) re-spawn them automatically once the update completes.

Long-running sessions should not silently lose tool capabilities mid-task.

Error Messages/Logs

No explicit error surfaced in the session. The only visible signal is that previously-working MCP tools begin returning "MCP server disconnected; deferred tools no longer available" when invoked via ToolSearch.

/mcp shows the affected server as disconnected. No restart attempt is logged.

Steps to Reproduce

1. Configure an MCP stdio server in .mcp.json (or install a plugin that ships one — e.g., Telegram MCP).
2. Start Claude Code. Confirm tools are available via /mcp (server shows "connected").
3. Begin a long-running session and let Claude Code perform a plugin autoupdate mid-session (or trigger one).
4. After the autoupdate completes, invoke any tool from the affected MCP server.
5. Observe: tool calls fail, /mcp shows the server as disconnected, no respawn occurs.
6. Attempt to recover by killing any stray child processes (python.exe / node.exe) via Task Manager — no respawn is triggered.
7. Only a full Claude Code restart re-spawns the MCP server and restores tools.

Environment: Windows 11 Pro, Claude Code CLI, PowerShell 7+.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.150

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_