[BUG] Horizontal scrollbar appears in sidebar chat panel (other extensions don't have this)

Description

The Claude Code sidebar chat panel shows a horizontal scrollbar when messages
contain long lines (e.g. long code identifiers, log output, file paths).
Other VS Code AI extensions that use the same sidebar panel (Qwen Code, Kilo
Code) do not exhibit this behavior — their content wraps properly without a
horizontal scrollbar.

Steps to Reproduce

1. Open Claude Code in the VS Code sidebar
2. Have a conversation where any message contains a long unbroken line

(long identifier names, log output, inline code)

1. Observe horizontal scrollbar appearing at the bottom of the chat panel

Expected Behavior

Content wraps within the panel width. No horizontal scrollbar.

Actual Behavior

Horizontal scrollbar appears, making the panel cluttered and requiring
horizontal scrolling to read content.

Environment

• Claude Code extension: 2.1.109
• Claude Code CLI: 2.1.108
• OS: Linux x86_64

Additional Context

Qwen Code and Kilo Code in the same sidebar panel do not show a horizontal
scrollbar. The fix is likely a simple CSS change: overflow-x: hidden or
word-break: break-word on the chat container in the webview panel styles.