- Remove hardcoded GRAD_COLS and MSG_GRAD_COLS module constants
- Add _default_green_gradient() and _default_magenta_gradient() fallback functions
- Add _color_codes_to_ansi() to convert integer color codes from themes to ANSI escape strings
- Update lr_gradient() signature: cols parameter (was grad_cols)
- lr_gradient() now pulls colors from config.ACTIVE_THEME when available
- Falls back to default green gradient when no theme is active
- Existing calls with explicit cols parameter continue to work
- Add comprehensive tests for new functionality
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>