v0.8.1

Programmatic theming

Derive a complete paired light + dark palette from a single brand color:

• createTimbalTheme, themeToCss, applyTimbalTheme / clearTimbalTheme
• TimbalThemeStyle, TIMBAL_THEME_PRESETS, ThemePresetGallery
• THEME_AGENT_INSTRUCTIONS for UI-generation agents

See CHANGELOG.md for full details.