[BUG] /mcp interactive dialogue hangs and freezes terminal input on resumed sessions

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?

Bug: /mcp interactive dialogue hangs and freezes terminal input on resumed sessions

Claude Code version: 2.1.119
OS: macOS 25.5.0
Terminals tested: iTerm2, macOS built-in Terminal.app

### Description

When resuming a Claude Code session (using --resume or continuing a previous session), the /mcp command opens its interactive dialogue but then completely freezes terminal input. No keypresses are registered — not arrow keys, not Escape, not Ctrl-C. The process stays alive but the UI is unresponsive. The only recovery is closing the terminal tab entirely.

This does not happen in a fresh session started from scratch — /mcp works normally there.

### Actual behaviour

The dialogue renders but the terminal input is completely frozen. Arrow keys, Escape, Enter, and Ctrl-C all have no effect. Requires closing the terminal tab to recover.

### Additional context

• Both MCP servers are responsive to direct tool calls during the freeze — the issue is in the /mcp UI layer, not the servers themselves
• Re-authenticating the Jira MCP server via chat before opening /mcp does not resolve the hang
• Starting a brand new session (not resumed) makes /mcp work normally
• Possibly related to #76838 (TUI renderer + stdin die mid-session)

What Should Happen?

### Expected behaviour

/mcp should open the interactive dialogue and respond to keyboard input normally, regardless of whether the session is new or resumed.

Error Messages/Logs

Steps to Reproduce

### Steps to reproduce

1. Start a Claude Code session with MCP servers configured (tested with github-wdf and sap-jira)
2. Complete some work, then end or detach from the session
3. Resume the session
4. Type /mcp
5. The interactive MCP status dialogue appears but accepts no keyboard input

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.119

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_