Remove the Rich-based textual renderer and all --mode modern references.
The console now runs exclusively in VT220 curses mode (green on black).
No external dependencies required.
Removed: console/renderers/textual_renderer.py, --mode flag, DEFAULT_MODE
Updated: main.py, config.py, README.md, console/README.md
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>