[FEATURE] Mermaid visualization

Preflight Checklist

• [ ] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I'm working with a lot of mermaid, claude can generate it, its quite nice.
But i have to copy past into a visualizer which is a bit painful.

Proposed Solution

i'd like to claude be able to directly render it in the term, and still allow a copy/past button.

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

_No response_

Additional Context

_No response_