[Bug] Final assistant message duplicated 7-10 times with progressive truncation

Bug Description
Title: Final assistant message is duplicated 7–10 times with progressive truncation

Environment:

• Claude Code CLI inside VS Code integrated terminal
• macOS (26.3 (25D122))
• Started occurring after upgrading to the current Claude Code version (no other changes — no VS Code update, no macOS update, no

config changes on my side)

Description:
After the assistant finishes a turn, the final chat output is rendered repeatedly — typically 7 to 10 times in a row — directly in
the terminal. Each repetition is a different length: the first instance is usually the complete message, and each subsequent
repetition is truncated by one or more lines from the end. By the last repetition, only the first few lines remain.

This happens on every turn, in every new session, reproducibly. It started with the current Claude Code version; the previous
version did not exhibit this behavior.

Steps to reproduce:

1. Open a new Claude Code session in the VS Code integrated terminal.
2. Send any prompt that produces a multi-line assistant response.
3. Observe the final response being printed multiple times with progressive line-by-line truncation.

Expected: The final assistant message is rendered exactly once.

Actual: It is rendered 7–10 times, each repetition shorter than the previous.

Notes:

• I have not changed any local configuration, did not update VS Code, did not updat…

Note: Content was truncated.