Plan Mode: session text scrolls away and disappears during Cogitating phase

Description

When in Plan Mode, the session text rolls up and disappears during the "Cogitating..." phase and never comes back. The screen ends up mostly blank — only the input prompt area and plan mode indicator remain visible at the bottom.

Steps to Reproduce

1. Enter Plan Mode (shift+tab to cycle to plan mode)
2. Submit a prompt that triggers extended cogitation
3. Watch the terminal during the "Cogitating..." phase

Expected Behavior

Session text (the prompt, cogitation status, and any streamed plan output) should remain visible and scroll normally as the plan is generated.

Actual Behavior

The session text scrolls/rolls upward and vanishes during cogitation. The screen goes mostly blank with only:

• The › Press up to edit queued messages line
• The ▌▌ plan mode on (shift+tab to cycle) indicator
• Empty space above

The plan output never renders back into view. The user is left staring at a blank screen with no way to see the planning output.

Screenshot

!Plan Mode blank screen during cogitation

(Screenshot shows: Claude Code v2.1.90 in Plan Mode. The "Cogitating... (1m 44s · ↓ 6.9k tokens)" indicator is visible at top, but all plan output text has scrolled away. The bottom 80% of the terminal is empty.)

Environment

• Claude Code version: 2.1.90
• Model: Opus 4.6 (Claude Max)
• Platform: macOS (Darwin 25.4.0)
• Terminal: macOS Terminal.app
• Shell: zsh

Additional Context

• This appears to be a recent regression — Plan Mode text rendering worked previously
• The cogitation phase shows tokens being received (6.9k tokens in the screenshot), but the rendered output disappears
• The issue persists after cogitation completes — the text does not reappear
• Observed in the desktop CLI, not yet tested in other environments

🤖 Generated with Claude Code