[BUG] SessionStart:clear systemMessage not rendered after /clear in the default TUI renderer (shown only in ctrl+o or fullscreen)

Preflight

Searched existing issues. #80882 is about the VS Code side panel; this one is the terminal CLI with the default renderer.

What's Wrong?

After /clear, a SessionStart hook's systemMessage (SessionStart:clear says: ...) is not shown in the default terminal renderer.

• 0/17 displayed, across plugin vs settings.json registration, hook latency 0 to 3 s, with and without a status line, with and without --debug-file.
• The hook's additionalContext reaches the model (17/17) and hook_system_message is written to the transcript (17/17).
• The line is visible in the ctrl+o transcript view, and after toggling back it also appears in the normal view. Resizing the window or pressing ctrl+L does not bring it up.
• With tui: "fullscreen" it is shown (2/2).

So a hook cannot use the transcript to tell whether its message was actually seen after /clear.

What Should Happen?

SessionStart:clear says: <message> is displayed after /clear in the default renderer, the same way the startup and compact messages are.

Steps to Reproduce

1. In an empty directory, create .claude/settings.json with a SessionStart hook that prints:

``json
{"systemMessage": "notice <random each run>", "hookSpecificOutput": {"hookEventName": "SessionStart", "additionalContext": "context <random each run>"}}
``

1. Make sure tui is not set to "fullscreen". Run claude: the SessionStart:startup says: line is shown.
2. Send one message, then run /clear.
3. No SessionStart:clear says: line is shown. Ask the model for the random token from additionalContext: it answers correctly. Press ctrl+o: the message is there.

Likely cause

The /clear hook messages are placed at the head of the new transcript, and the default renderer does not repaint rows it has already printed, so a message inserted above the current output never gets drawn.

Claude Code Version

2.1.281 (native install)

Platform

Anthropic API (Claude subscription)

Operating System

macOS (Darwin 25.1.0)

Terminal/Shell

Terminal CLI inside tmux, zsh.