Add RTL (Right-to-Left) support for chat output in VS Code extension

Description

When Claude responds in RTL languages (Hebrew, Arabic, Persian, etc.), the text in the chat panel is displayed left-to-right, making it difficult to read.

Expected Behavior

RTL text should be displayed right-to-left in the chat panel, either by:

• Auto-detecting RTL languages and setting dir="rtl" on the relevant text blocks
• Adding a setting (e.g., claude-code.chatDirection) to allow users to configure text direction

Current Behavior

All chat output is rendered LTR regardless of language content.

Environment

• Claude Code VS Code Extension (Windows 11)
• Language: Hebrew

This affects all users who work with RTL languages.