[BUG] [CC Desktop] Sticky user-prompt overlay collapses readable area when scrolling long responses

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?

Environment

• CC Desktop version: <fill from Claude Code → About>
• macOS: <fill from About This Mac>
• Conversation has 2+ Git repos active (PR-status plates visible at bottom)

Actual behavior
At a certain scroll position, the user-prompt block becomes effectively sticky and visually overlaps Claude's response. With Git PR-status plates pinned at the bottom (showing Create PR for each repo), the readable area between them collapses to a narrow strip — sometimes only 1–2 lines tall. The response is unreadable without resizing the window or hiding the PR plates.

The effect is proportional to:

• Length of the user prompt (longer prompt → larger overlay)
• Number of Git repos in the working tree (more PR plates → less bottom space)
• Window height (smaller window → faster collapse)

Impact
For sessions with multi-repo workspaces and substantive prompts (the normal case for any real engineering task), the response area becomes unusable mid-scroll. Workaround so far: shrink the window or close all but one repo's PR plate, neither of which is acceptable for normal work.

Screenshot
[attach the two-session screenshot — left: Kleos session, right: AI Skills Conf Workshop session, both showing the prompt overlay covering most of the response]

Suggested fixes

1. Make the user-prompt block scroll with the content rather than become sticky on certain scroll positions, OR
2. Add a collapse/expand toggle on the user-prompt block (one click to dismiss the overlay while reading), OR
3. Limit the user-prompt block's max-height when sticky (e.g. 3 lines + ellipsis with hover to expand).

What Should Happen?

Expected behavior
While scrolling, the user message scrolls off the top (or collapses to a small reference) so the response area uses the available height. PR-status plates at bottom stay compact.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce

1. In CC Desktop, submit a long user prompt (multi-paragraph, ~500+ chars).
2. Wait for Claude to produce a long response (~10+ paragraphs).
3. Scroll down through Claude's response.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.23 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_