[BUG] VS Code chat: scrollbar stops short of assistant response after long pasted content, in both sidebar and full editor tab

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?

TL:DR
When a long block of text is pasted into the chat (either as a plain message that's then expanded via "Show more", or as arguments to a custom skill/slash command like /grill-me or /checkin, which renders already expanded with no toggle), the assistant's response becomes unreachable by scrolling.

The scrollbar is present and moves, but its maximum scroll position stops short of the response — it never comes into view. This happens regardless of panel width or type: reproduced in the sidebar at both narrow and maximum width, and in a full editor tab scrolled to the hard bottom.

No workaround found — widening the panel or moving to an editor tab only appeared to help with shorter pastes, not longer ones.

Longer response:
Environment:

• Claude Code VSCode native extension, version 2.1.226 (darwin-arm64)
• macOS (Darwin 24.5.0)
• Reproduced in the sidebar (narrow and maximum width) AND in a full editor tab

Actual behaviour: Scrolling reaches its maximum position while still inside the pasted content — the assistant's response is never reached, regardless of panel type (sidebar or editor tab) or width. Confirmed via screenshot: scrolled to the hard bottom in a full editor tab, still only pasted content is visible, no response.

No working workaround found: widening the sidebar and moving the chat to a full editor tab were both tried and neither resolves the issue for sufficiently long pasted content — both only appeared to help in earlier, shorter-content tests.

Confirmed not skill-specific: reproduces identically with two unrelated skills (/grill-me and /checkin) and with plain-message pastes, pointing at a shared scroll-container/rendering bug.

Related issues: possibly adjacent to #78093 (tab bar unreachable at narrow widths) and #18105 (text fails to wrap on panel resize).

Screenshots:
BUG:
With narrow sidebar
With no skill invocation (just plain text)
With "show more" toggle clicked

• Can see text truncated
• Can see "show less" toggle
• BUG Cannot see assistant's response

<img width="675" height="987" alt="Image" src="https://github.com/user-attachments/assets/081cb2cb-bc71-4bb6-965e-36994ee19897" />

BUG:
With narrow sidebar
With /checkin (or any skill) invoked

• There is no text truncation
• Cannot see "show less" toggle
• BUG: Cannot see assistant's response

<img width="681" height="995" alt="Image" src="https://github.com/user-attachments/assets/411418f3-6657-4da2-9d53-419dbfd16722" />

POTENTIAL BUG:
With maximum width sidebar (reproducible with full editor also)
With no skill invocation (just plain text)
With "show more" toggle clicked

• Can see "show less" toggle
• BUG: Cannot see assistant's response

<img width="1388" height="993" alt="Image" src="https://github.com/user-attachments/assets/d5b40ea5-6f26-4a78-acac-337e3a5ed2a4" />

BUG:
With maximum width sidebar (reproducible with full editor also)
With /checkin (or any skill) invoked

• Cannot see "show less" toggle
• Cannot see assistant's response

<img width="1389" height="1003" alt="Image" src="https://github.com/user-attachments/assets/6956ce70-c949-4c3c-8291-f94327fc3e55" />

What Should Happen?

Expected behavior: The scroll container should account for the full height of the conversation including the response, and the response should always be reachable by scrolling.

Screenshots:
EXPECTED/GOOD:
With narrow sidebar
With no skill invocation (just plain text)

• Can see text truncated
• Can see "show more" toggle
• Can see assistant's response

<img width="670" height="388" alt="Image" src="https://github.com/user-attachments/assets/eef4b491-a345-4e30-bb6a-378bb4b43dbd" />

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

1. Open Claude Code chat, either in the sidebar or a full editor tab.
2. Paste a sufficiently long multi-paragraph block of text (longer reproduces more reliably) as a plain message, submit, and click "Show more" to expand it inline.
3. Invoke a custom skill/slash command (reproduced with /grill-me and /checkin) with the same long text as its arguments — this renders already expanded, with no toggle.
4. Scroll down as far as possible to reach the assistant's response.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Code VSCode native extension, version 2.1.226 (darwin-arm64)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_