[BUG] Remote control: teammate messages render as security-reminder boxes without the message

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?

Agent Teams + remote control (/rc), viewed from the Claude desktop app: each teammate
SendMessage to the lead renders as a gray box containing only the injected security reminder
("Another Claude session sent a message: ... that's permission laundering."). The message
itself is not shown. Multiple messages produce a wall of identical boxes.

The CLI renders the same event as a compact "Message from @<teammate>" line. Delivery works —
the lead responds to the content.

What Should Happen?

A compact notification like the CLI's, not the raw injected reminder without the message.

Error Messages/Logs

Steps to Reproduce

1. Linux, inside tmux: lead session with CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1, teammateMode

tmux; enable /rc and attach from the desktop app.

1. Lead spawns a teammate; teammate sends the lead a message via SendMessage.
2. View the exchange in the desktop app.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.218 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

<img width="892" height="284" alt="Image" src="https://github.com/user-attachments/assets/e0eafe98-cebe-43a3-858c-3b84bffc979f" />

• Claude Code v2.1.218, remote Linux machine, tmux split-pane teammate display
• Desktop app on Windows v1.24012.0