[FEATURE] VS Code Extension: option to disable auto-collapsing of user prompts in chat history

Summary

In the VS Code extension, multiline user prompts are collapsed behind a "Show more" button in the conversation history. There's no setting to control or disable this behavior.

Problem

When reviewing a conversation, collapsed prompts make it hard to see what was actually said without clicking "Show more" on each one. For users who write detailed, multiline prompts — particularly those using Claude Code as an ongoing collaborative partner rather than a quick task runner — the conversation history becomes a wall of collapsed blocks that require individual clicks to review.

This is a regression relative to the CLI / Terminal UI, which displays the full text of user prompts in the conversation history without collapsing them. The VS Code extension appears to be the only Claude Code surface that truncates user input this way.

Requested behavior

A setting (e.g. claude-code.autoCollapseUserPrompts: boolean or a configurable line threshold) to control whether user messages are collapsed in the chat panel. Ideally, the default would match the CLI behavior (show full text), with an opt-in collapse for users who prefer it.

Related issues

• #39809 / #38674 — "Show more/less" toggle behavior
• #11334 — configurable auto-collapse threshold for bash output
• #3412 — pasted text collapsing