[FEATURE][CLI] Markdown renderer support in Claude Code CLI

Preflight Checklist

• [x] 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

Currently, Claude Code CLI displays raw markdown syntax in responses. When Claude outputs formatted content, users see the literal markdown characters (**bold**, # Header, code blocks, etc.) rather than rendered formatting.
This reduces readability, especially for:

• Code blocks (no syntax highlighting)
• Tables (raw pipe characters instead of aligned columns)
• Headers (just # symbols)
• Lists and emphasis
• Mermaid diagrams
• UML diagrams
• Sequence diagrams
• ERDs

Proposed Solution

Implement a terminal markdown renderer (similar to tools like glow, mdcat, or rich) that renders:

• Syntax-highlighted code blocks with language detection
• Mermaid diagrams
• UML diagrams
• Sequence diagrams
• ERDs
• Styled headers with visual hierarchy
• Bold/italic text styling
• Properly aligned tables
• Colored/styled lists
• Clickable hyperlinks (in supported terminals)

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

1. Plan review
2. Agent creation
3. Skill Creation
4. Rules creation

Additional Context

_No response_