[BUG] "SHOW LESS" toggle broken after recent update — long responses become permanently hidden

Description

After a recent update, the "SHOW LESS" / "SHOW MORE" toggle for long tool results or user messages no longer works correctly. When a conversation includes long content (e.g., multi-line CLI commands with JSON responses), the collapsed content cannot be expanded — the response remains hidden/truncated with no way to reveal it.

Steps to Reproduce

1. Start a conversation that includes a long message — for example, a grpcurl command with a multi-line JSON response pasted inline
2. The message gets collapsed with a "SHOW LESS" / "SHOW MORE" toggle
3. Clicking "SHOW MORE" does not expand the content, or the toggle is unresponsive
4. The assistant's answer that follows the long content is also hidden/cut off

Expected Behavior

• "SHOW MORE" should expand the collapsed content
• "SHOW LESS" should collapse it back
• The assistant's response should remain fully visible regardless of the collapsed state of prior messages

Actual Behavior

• The toggle does not respond or fails to expand
• The assistant's answer is hidden behind the broken collapsed section with no way to view it

Environment

• Platform: macOS
• Interface: VS Code extension (Claude Code)
• Trigger: Appears to have started after a recent update

Additional Context

This is reproducible when pasting long CLI output (e.g., grpcurl JSON responses ~30+ lines) into the user message. The issue makes it impossible to read Claude's response when it follows a long input block.