- Added render_mermaid tool to convert Mermaid diagrams to ASCII output with configurable rendering options.
- Added renderMermaid.enabled setting to control availability of the render_mermaid tool.
- Changed Mermaid rendering from PNG terminal graphics to ASCII text format across theme and TUI components.
- Migrated mermaid utilities from pi-tui to pi-utils package with new ASCII rendering functions.
- Removed PNG-based mermaid rendering APIs (getMermaidImage, renderMermaidToPng) in favor of ASCII alternatives.