[BUG] Text output duplicated when tool calls are mixed in the same response

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?

When the assistant outputs text and then calls a tool in the same response,
the text before the tool call gets displayed twice — once during streaming,
and again after the tool call completes.

This did not happen in earlier versions. Games and other scenarios that
require text + tool calls in the same turn used to work fine.

Client: Claude Code iOS app
Version: 2.1.214

What Should Happen?

When the assistant outputs text and calls a tool in the same response, the text should only be displayed once.

Error Messages/Logs

No error messages. The text output is simply duplicated in the UI.

Steps to Reproduce

1. Ask Claude to do something that requires both a text reply and a tool call in the same turn (e.g., "say hello and save this to a file")
2. Claude outputs text first, then calls a tool (like Write or an MCP tool)
3. The text that appeared before the tool call gets displayed a second time after the tool call completes

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.214 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_