suggest a chat.tangentModeIcon setting

[wenijinew]

Due to font config, the icon (tangent mode is active) currently might not be readable.

So, making it configurable would be helpful.

[github-actions]

🤖 Potential Duplicate Detected

This issue appears to be similar to:

• #5305: Add Visual Indicators for Spec Mode vs Vibe Chat Mode (85% similar)

What happens next?

• ⏰ This issue will be automatically closed in 3 days
• 🏷️ If this is not a duplicate, you can prevent automatic closure by adding a comment or reacting with 👎 to this message.
• 💬 Comment on the original issue if you have additional information

Why is this marked as duplicate?
Both issues request visual indicators/configuration for chat mode display - the new issue wants configurable tangent mode icon due to readability, while #5305 wants visual indicators to distinguish between chat modes. Both address the same core problem of unclear visual state in the chat interface.

[github-actions]

This issue has been automatically closed as it appears to be a duplicate of #5305.

If you believe this is incorrect, please comment on this issue and a maintainer will review it.