TUI Enhancements: Streaming, Markdown, Provider Info

[laynepenney]

Summary

Enhancements to the Phase 6 TUI implementation.

Background

The initial Phase 6 TUI implementation provides a basic chat interface. These enhancements will bring it closer to feature parity with the TypeScript version.

Enhancements

Streaming Text Display

• Real-time text streaming during AI responses
• Token-by-token rendering
• Streaming cursor/indicator

Markdown Rendering

• Basic markdown support (bold, italic, code)
• Code block syntax highlighting
• Link handling

Provider Info Display

• Show current provider/model in status bar
• Token usage display
• Cost tracking display

Diff Rendering

• Unified diff display for file changes
• Syntax-highlighted diffs
• Before/after comparison

Session Integration

• Session picker for resume
• Session history browsing
• Auto-save integration

Additional Commands

• /model - Switch model
• /provider - Switch provider
• /session - Session management
• /compact - Context compaction

Related

• Phase 6 TUI: feat(codi-rs): Phase 6 Terminal UI - ratatui based interface #232 (merged)
• Phase 5.5 Session: feat(codi-rs): Phase 5.5 Session & Context - persistence and windowing #231 (merged)

Priority

Medium - nice-to-have but not blocking